Bogie Seals - Renewal and Maintenance - Important

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1 Bogie Seals - Renewal and Maintenance - Important The following comments and statements revolve around my discoveries and observations. My findings and outcomes are not necessarily gospel, but are likely fair representations of reality. I would welcome comments and thoughts and corrections (if any) on the following findings and discussion. I have been working on the suspension of a weasel and I have found issues with the bogie wheel shaft seals. As I disassembled the bogies for inspection, I found that all of the seals on the hull side, were completely out of their retaining bores. There was a mixture of both original and the newer style replacement C/R seals installed throughout the bogie assemblies. The rest of the bogie seals were either no longer seated in the bogie housings and spinning out of their respective retaining hubs, or the seals were almost completely pushed out, with their sealing lips destroyed. Many of the seal s rubber portions were torn. The interiors of the wheel shaft housing assemblies were mostly full of grease, but there was also water contained within, as the grease seals were no longer doing their job. How and why had these seals had been forced out of their retained positions? As I began to look at he seals, I noticed that they all had been installed with the sealing lip facing inward. At first thought, this sounds normal. This is the case with other seals I have installed. Jeep seals for example; transfer case or pinion seals. But with the weasel bogie, what are we really trying to use this seal for?

2 The following images are of the seals as they were found upon disassembly. Image 1 This picture shows a new C/R seal (part # 12391) that has been forced outward from it s housing. As shown, it is out about 2/3 from where it should be normally positioned. I believe it would have been completely dislodged, if the rubber lip had not torn free, allowing grease to subsequently pass freely past. Image 1 Image 2 These seals are a newer and thinner bodied style seal, and they have also been pushed outward. Also, in some cases they had the bogie wheel rivet impressions made upon them. This seal is out of its retained position and you can see rough a shiny scuff mark where the seal body is being chaffed by spinning bogie wheel rivets. The internal rubber sealing guts are gone. Very interesting

3 Image 2 Image 3 Here is a pic of these thinner C/R seals. I have placed two beside each other. One seal shows the seal body 'shaped' as it should be normally and the other showing a damaged seal body 'splayed' outward. Image 3

4 The seal bodies that have ballooned are from pressure created by the grease applications when using a grease gun. But as it turns out, there is a bigger issue here. This seal has been installed incorrectly. Image 4 In this image, you can see were an original seal has impressed itself against the inside rivets of the bogie wheel housing. This situation has occurred due to incorrect installation of the seal and the application of grease. Image 4 The original style seals have a deep body. It will travel outward until it contacts the inside of the bogie. At this point the body of the seal is still in held in it s home. With further grease applications the metal is then splayed outward.

5 Image 5 and 6 This pic shows a ballooned original seal and the inside of a bogie wheel. When the seal is turned over and inset down onto the shaft, the semi circular impressions on the seal body, will match up perfectly into the bogie wheel rivets. Also shown are the marks made from the forced out seal contact with the rivets. Image 5 Image 6

6 Image 7 The 'ballooned' body seals are seals that were installed with their sealing lip facing inward. The steel seal body was pushed outward and then ballooned outward by grease pressure. The lip in would not allow for much if any grease to escape past. Image 7 So the answer to HOW did this happen; is that these seals have been moved, dislodged when greasing the bogies. The answer to WHY it happened; is because the seals had been installed with their sealing lips facing in towards the housing. This has prompted me to do some investigating and try to come up with some answers, most notably, what needs to be done to prevent this damage and displacement from occurring. I also wanted to find out how bogie wheel greasing was affected by installing seals facing one way or the other.

7 Image 8 Original style seals with a leather lip/seal. The seal shown on the right is how it should normally look. The seal on the left has ballooned from grease pressure and it has pressed hard enough against the bogie wheel, to leave rivet impressions. Impressive! pun intended Image 8 Determining the sealing contact point I wanted to see where the sealing lip made contact with the bogie sealing shaft when the seal was installed lip outward and lip inward. To be clear, when I say lip inward, I am indicating the installation of the sealing lip facing inward towards the bogie wheel support housing (Ord # B266642) and lip outward is vise versa.

8 I wasn t sure if the sealing lip would make adequate contact when facing inward. I used a marking 'blue' to help visually see the contact positions. Image 9 Lip 'IN' This photo shows the lip facing in contact point. The contact is at the outer most point of the bogie wheel sealing surface. Actually, it is at the edge of the machined shaft sealing surface of the bogie wheel, where the installation bevel is located. This is not a good lip position. This revelation alone is enough in itself to steer me away from thinking that the seal could or should be installed lip facing towards the housing. but I am getting ahead of myself, let s read on. Image 9 Image 10 and 11 Lip OUT This photo shows how far inward on the shaft, the lip contact surface should be, when installed lip facing outward, as it should normally be. These are contact sealing positions for original and C/R seals.

9 Image 10 Image 11 Seal installation notes - Install sealing lip OUTWARDS The TM9 (manual) indicates to install these seals with their lip facing OUT. This is corroborated by the orientation of the interior Guide wheel seal and the interior Drive and Idler wheel seals.

10 You can refer to figure 168 on page 279 of TM9-772 dated 1945 This cross-section view shows the seal installed lip facing outward. These seals are to be installed this way to help expel excess grease and contaminants and also to keep water out. I believe that in some cases it might help to install the seal with a thin coat of gasket sealant or similar binding substance to help bind the seal body to the casing. If the housing is worn or you find the seal taps in too easily, I have used Permatex Ultra Grey with success. If the seal body was not binding in nicely, it will get pushed out even with hand pump grease gun.

11 Image 12 This is the original style seal installed properly, lip facing outward. The seal body should not be pressed in further than the outer edge. Image 12 Image 13 If you are using the leather seals, they MUST to be soaked in oil to wick up and soften the leather before installation. The leather seals need to be cleaned of packaging Cosmoline (if present) and allowed to soak up the softening lubricating fluid. A 30-weight oil is a fine choice. Let the seal soak for a day or two. Image 13

12 Image 14 On these old seals, I also knead the leather a bit, and I stretch the lip just a bit, by sliding the seal over a deep socket of a diameter just slightly larger than the leather seal lip diameter (view photo example). These are relatively small seals that could use a little bit of help. The leather can be quite stiff, it needs to be pliable. Image 14 Image 15 C/R seals do not need to be pre-soaked, but should have a modest amount of grease applied to the mating lip surface as a pre-lube. Photo of a C/R seal beside and original Weasel bogie leather seal. Image 15

13 Image 16 Image 16 and 17 When using new type open bodied C/R seals, the open side normally goes toward the grease/oil (interior) and the closed side goes facing outward. As we are using these newer seals in an application it was not originally intended for, this will not be the case. These seals should not be installed on Weasel bogie wheels with the lip facing inward. Internal grease pressure will displace the seal. A liberal application of grease around the exterior of the seal/spring will protect the seal, during its unconventional installation. Leave the spring on the seal, it helps the rubber lip to keep its shape and apply sealing lip tension. Apply a coating of grease to the sealing surface lip, when assembling and installing. Image shows partially completed exterior grease application.

14 Image 17 You may also wish to apply a gasket maker (sealer/adhesive) to help bind the seal body in its installed position. But it is not a requirement. The performing of tests Due to my finding the bogie seals being damaged, forced out of place, and my having a curiosity as to why, I decided to do some experiments on a bogie wheel assembly. Two of the questions I had was how long did it take for this to happen and could it possibly be ok? to install the seal lip inwards? I have identified each test with a number for discussion or reference, if needed. I started testing for the results of the application of grease with different bogie seal orientation installations, to see what effect this may have (this is the lip in / lip out thingy).

15 With these tests, the interior of the bogie shaft casing was well packed and full of grease as a starting point. Where used, NOS original seals were soaked 48 hours. The bearings were packed with grease. The newer style Chicago Rawhide (C/R) seals did not require any preparation other than a light wipe of the sealing lip with grease. In these tests, I used a hand pressure lever operated grease gun (not unlike the one supplied with the weasel), also an air powered grease gun, and an electric operated grease gun (for comparison). Tests with Original seals installed lip out Test 1 Casual pressure application with hand operated grease gun. Result: seals stayed intact/in place, with grease visibly passing by the leather seal Test 2 Quick repetitive strokes with hand operated grease gun, with no regard for the feeling of some backpressure on the stroke application. Result: I did this test 3 times. There was some visible escape of grease past the leather seal and of note; the body of one seal began to be forced outward on 1 of the 3 tests. The opposite seal stayed in place. I am assuming that once a seal was moving, it was easier to keep that seal moving, than dislodge the other. Test 3 I used the power-operated grease gun(s) with causal repetitive applications. Result: Immediate forcing of the body of one seal outward, with little grease bypass the leather seal. It was very interesting to see the seal bodies immediately being forced out. It would seem that your seals don t even stand a chance with power-operated guns. And remember, this is the application of grease with the seals facing the proper way!

16 Tests with C/R seals installed lip out Test 1 Casual pressure application with hand operated grease gun. Result: seals stayed intact and in place, with grease visibly passing by the rubber seals. Test 2 Quick repetitive strokes with hand operated grease gun, with no regard for the feeling of some backpressure on the stroke application. Result: There was visible escape of grease past the rubber seals and the seals were intact. Test 3 I used the power-operated grease gun with causal repetitive applications. Result: Lots of grease had passed by the seal lips. I found that one of the seals had moved slightly outward when using air operated gun, but not with electric gun. Test 4 I dialed down the air powered grease gun to 40 psi from normal operating psi of psi. Result: I found that with casual applications, the lower air pressure operated grease gun did not move the seals out of their home. But there was no feel for what was going on with the power gun. The C/R seals did very well during greasing tests, the rubber seals are more flexible than the leather ones. They allow an easier flow of grease past the seal. But they are more fragile if they get pressed out of their bores through greasing, and are subject to catastrophic failure if incorrectly installed lip inwards.

17 Dislodging Tests Thought I'd check to see how long it would take to force a seal out with grease application. I installed the original seals essentially flush with the housing body, lip out. For fun, I put a pressure gauge in the casing body to see what pressures I would achieve while using a hand pump grease gun, both with seals installed lip out and lip in. I initially started with a 100 lb. gauge and then used a 1000 lb. gauge. Image 18 Test with ORIGINAL seal installed lip OUTWARD. Test 5 Results: No appreciable pressure was read on the gauge, with the seals installed lip out, while using proper grease application. Grease casually passed by the sealing lip. Which was a boring, but pleasing result.

18 Tests with ORIGINAL seal installed lip INWARD. In spite of having discovered that, if the original seal is installed reversed (lip in), that there is or could be, little or NO proper contact with the bogie wheel surface, I tested 'lip in' anyway. In my findings, the seal lip face when installed inward, was binding against the bearing or was just barely making contact with bogie sealing surface. Test 6 Results: I was getting pressure readings of around 100 pounds while pumping in grease when seals were installed lip inward. One or both seals were noted to be moving outward from their retained positions, with each of only 4 strokes! I believe that you can expect this to occur, but you may find that you could rectify this if relief valves are installed. (maybe) Test 7 Results: With hand pump grease applications, the seals had forced themselves against the inside of the bogie wheel. It only took about 10 strokes, with fluctuating pressures indicating 100 s of pounds, to completely dislodge the seals. Test 8 Results: The seals were (grease) pumped outward and reached the contact surface of the inside bogie wheel rivets. Once they were pressing against the bogie, it began to reach values of 1000 pounds and more. With continued application of grease, the metal seal body began to distort, and quickly ballooned outward, leaving semi circular rivet impressions on the metal seal body. See photos attached. Image 19 and 20.

19 Image 19 Image 20

20 So, I immediately had my answer to my questions, which as it turns out are linked together. My question: how long did it take for this to happen and is it ok to install the seal lip inwards? Answer: Once the housing cavity is full of grease, if the seals are installed reversed (lip facing inwards), the seal body dislodging effect is immediate. With each greasing stroke, the seal is pressed further outwards from its containment. This reinforces that the seal should not be installed with the sealing lip inwards. One thing is for sure; greasing should be done in a slow casual fashion. AND from my tests... power grease guns are not to be used on bogies. What about grease pressure relief valve fittings? Would they alter the outcomes? Would they help me sleep better at night, knowing they were installed? Oh no more questions! I smell the need for some more experiments Wow! Great to see you re still with me! You re half way through. You deserve a break to use the facilities and maybe a beer. But come back, cause it gets more exciting from here on in, with an exciting greasy finish.

21 Grease Pressure Relief Valve fittings While working on this bogie seal expose, I have had discussions about the use of pressure relief fittings. After all, Studebaker had unwittingly provided for the easy installation of this device on the interior threaded port of the bogie housing. The 1/8 NPT thread was exactly what the doctor ordered for ease of relief fitting installation. I wondered if they would relieve any of the stress of greasing the bogie. I wasn t planning on installing any of them on my weasels but I was very curious about one thing in particular. Would these relief valves prevent seals from being forced out by grease pressure? Image 21

22 Performing Relief Valve Tests I purchased some Alemite brand plunger style 1-5 psi relief valves (Image 21, fitting on the right) and some Lincoln brand ball style 1-5 psi relief valves (left). I installed the valve on the interior port. I tested with both original style and C/R seals. The numbers indicate that the relief opens by 5 psi and will close as the pressure drops towards 1 psi. The ball style reliefs do not work well for our application (discussed later). My recommendation is use Alemite reliefs. Alemite installed see Image 22 There are two product numbers that come to mind from Alemite, # ( psi relief) OR # (1 to 5 psi relief) Image 22

23 ORIGINAL Seals installed lip OUTWARD Test 9 - original seals - Alemite plunger style relief valve. Using a hand lever type grease gun I applied slowly at first, then rapid strokes and the relief valve allowed grease to exhaust out the fitting. When I disassembled the wheel, grease had also passed by the seals, as it should have. Image 23 Test 10 - original seals - Alemite plunger style relief valve. I reassembled the bogie and then used an air powered grease gun. The relief fitting dispensed grease with each stroke. When I disassembled the unit, the bogie seals had passed grease, without moving the bogie seals from their installed positions. This was good news. Image 23

24 ORIGINAL Seals installed lip INWARD Test 11 original seals - Alemite plunger style relief valve. Using a hand lever type grease gun I applied slowly at first, then more rapid strokes and the relief valve allowed grease to exhaust out the fitting. When I disassembled the wheel, grease had not passed by the seal, as expected. But the exciting news was, the seal bodies did not appear to have moved. Test 12 - original seals - Alemite plunger style relief valve. I reassembled the bogie and then used an air powered grease gun. When grease was applied, the relief fitting dispensed grease with each stroke. When I disassembled the unit, the bogie seals had passed some grease BUT unfortunately, the pressure/volume from the power grease gun, DID move the seals outward! Image 24 Image 24

25 Even with pressure relief fitting (valve), the power grease gun, forced both bogie seals from their installed positions. Image 25 This test re-enforces that you should not use a power-operated grease gun to grease these fittings, even with relief valves. Image 25 Next: Tests using the C/R (Chicago Rawhide) seals Testing the C/R Seals installed lip inward Test 13 - Newer style C/R brand seals - Alemite plunger style relief. With a hand lever type grease gun I applied slow at first, then more rapid strokes, and the relief valve allowed grease to exhaust out the fitting. I didn t feel excessive back pressure on my greasing strokes. When I disassembled the bogie wheel, grease had not passed by the seal, as I had expected. Both seal bodies HAD moved. Even with relief fitting! Image 26 C/R seals are not as robust as the original seals. When the seal is installed lip in (incorrectly), you run the risk of tearing off the rubber sealing lip.

26 Image 26 Test 14 - I reassembled the bogie and then used the powered grease gun. When grease was applied, the relief fitting dispensed grease with each stroke. Upon disassembly, the bogie seals had passed some grease BUT unfortunately, the pressure/volume from the power grease gun, DID move both seals outward! Even with pressure relief fitting (valve), the power grease gun, forced both bogie seals from their installed positions. C/R Seals installed lip outward Test 15 Newer C/R brand seals - Alemite plunger style relief valve. With a hand lever type grease gun I applied slow at first, then more rapid strokes, and the relief valve allowed grease to exhaust out the fitting. I didn t feel excessive back pressure on my greasing strokes. When I disassembled the bogie wheel, grease had passed by the seals, as well as out through the relief fitting. The seal bodies remained unmoved. Image 27

27 Image 27 Test 16 - C/R seals - using Alemite plunger style relief valve. I reassembled the bogie and then used a powered grease gun. When grease was applied, the relief valve fitting dispensed grease with each stroke. When I disassembled the unit, the bogie seals had passed the grease without moving the seal bodies. End of tests

28 A note regarding Ball style pressure relief fittings I installed a Lincoln ball style pressure relief valve to see how much grease it would pass. This style fitting has very small grease exhaust ports. I suspected that it may not relief as quickly as the plunger style relief fitting. My concerns were confirmed. The ball valve style relief fitting does NOT pass excess grease very quickly. If you are going to install grease pressure relief fittings, do not use the ball style. The plunger style is the much better choice to use. Image 28 Ball style valve shown with fine strings of relief grease Image 28

29 Image 29 Image 30 Image 30

30 Pressure relief valve test conclusions Results indicate that when installed lip inwards (backwards), the original style seals will be forced out of their retained positions, EVEN with pressure relief valves installed. These seals should not be installed lip inwards, without or even WITH relief valves. But to be fair, the seals did stay intact when grease was casually applied. Properly installed seals do not require relief valves, but may be a nice addition and piece of mind. It was also nice to find that the seals did not get forced out when power lubrication was used. Results would indicate that the newer style C/R seals would be pressed out even with relief valves, when installed lip incorrectly with the lip inwards (backwards). C/R seals, when installed lip outwards, will be not be forced out of their retained positions, with pressure relief valves installed. The rubber C/R seals were capable of passing grease outward more readily, which would indicate that there is probably no reason to install reliefs. They seem to do just fine on their own, using normal lubrication technique. Notes on the Original Weasel bogie seals For the most part the seals are quite usable. I have found some of these 60 year old leather seals to be very stiff and other ones much more pliable. You need to prep these leather seals carefully. The leather portion of the seal needs to be flexible not hard. I have found a very firm leather seal can potentially brought back to life, by warming it under a heat lamp or other warming source (no microwave ovens). First you MUST remove all wrapping and cosmoline from the seal and the leather portion must be wiped clear of all preservatives. Kneed and work the leather so it feels pliable. Then immerse the seal into a light weight motor oil for at least 24 hours, then work the seal. You can repeat the process in an attempt to get the leather more flexible. You may wish to use a penetrating oil for wicking up into the leather. Take care not to nick or damage the leather.

31 General Conclusions - Bogie seals should be installed as originally intended. With the sealing lip facing out to the bogie wheel. - New C/R seals, part # 12391, will work just fine. -The use of power-operated grease applicators (guns) should be prohibited. Here s the thing. Although I was able to dial in (down) an air operated grease gun to not push out the C/R seals, there still is some potential risk. The electric gun did not push out the C/R seal, but there is still not feel for it all. The original style seals, if you use them, do NOT like power operated guns. - Relief valves do not ensure your seals will stay intact and seem not necessary if the seals are installed lip outward, as intended. If you are an aggressive luber, they may help. - When applying grease, do so casually, noting the feel of any backpressure and keeping it to a minimum. Once the housing cavity has been filled, all further grease re applications could likely be kept to 3-5 strokes per zirk grease fitting. Foreign contaminants will only likely enter in from the seal face. A few strokes should expel this. - Proper technique of grease application to the bogie assemblies will not force out the seals. Contaminated grease will be expelled out the bogie grease seal as intended when they have their sealing lip facing out. - The grease introduced into the bogie axle housing is successfully contained within the housing when the seals are installed with the outward facing sealing contact lip. - Inward facing seals will not allow for expulsion of old and contaminated grease. Seal bodies will be displaced when greased. - Seals must bind into to housing when installing to ensure they won t get pressed out, even with hand pump greasing. If you feel the seal slipped in too easily, glue it in as described. - No reliefs are required, with the use of proper greasing techniques, without a power pressured greasing applicator.

32 C/R seals - product number The commercially available C/R brand seals are the only ones that most weasel owners will be in a position to access. These C/R seals were not manufactured for use on weasels. It just happens that this particular seal has the correct critical dimensions necessary. You may find seals from other manufacturers like National (Federal Mogul), these seals can be found using the same code number. Generally it is NOT a common off the shelf seal. Quantities could be limited. A complete seal replacement job requires 32 pieces! While installing, you could bind the seal in place using gasket glue, but it is not required. In my tests I used Permatex brand spray gasket. I sprayed some in a cup and then applied the goo to the seal and housing with a small applicator. If the seal binds in nicely when installing then you probably don t need to worry about it being pushed out. Install them lip facing outward and the body of the seal flush with the housing. With your finger, pack the exposed side of the seal with grease, to coat the tension spring. As you service the bogie (grease it), it will look like this soon enough anyway. Apply a small amount of grease to the radial lip surface, to lubricate it before assembly. I like the idea of no relief, myself, but if is something you want to install; it might add a measure of comfort. Personally I prefer the idea of all the grease application flowing the possibly contaminated grease, outwards past the seals and the C/R seals performed well in that task. Hope you enjoyed reading my findings and discoveries I m gunna go get cleaned up now Brock