1981 931B Transmission leak and confirmation help

[pittsburgh cat man]

Try this https://avspare.com/caterpillar/

 

[surferboy120]

Try this https://avspare.com/caterpillar/

Thats the diagram source..... weird my parts book doesnt show that diagram. Would have made my life a lot easier.

Thank you I appreciate it

 

[surferboy120]

Just a quick update that I got my parts but also found that Part # 11 in the diagram which is a 46 toothed gear (part of group 9P7243) needed one of the bearings replaced (9S7950) as it had made light contact with the bearing that I was replacing. So with that said I ordered the bearing but also doing a good check on the shims as they may be to tight on clearances. Hopefully the bearing gets here later this week and once pressed on I can check the required tolerances with the shims. Shims are #12 - SHIM PACK 1.57MM(.062IN)THK

I am buying a shim stack to replace and compare what I have since I am in there and its the only other thing that looks to have wear surprisingly....

Everything else looks great with no wear outside of what is mentioned. I feel good that at least I know why the seal I was originally replacing had wear on its metal casing since it was lightly making contact with the bearing. Not a good thing at all.

 

[surferboy120]

Good morning.... Does anyone have a lead on good parts dealers for CAT parts? I am having some trouble finding the shim pack I need Caterpillar 6P-0679 ... Cat says they have it but will take a month to get and the price is not horrible but not great. I am just trying to find other options although I am not seeing any online.

Thank you in advance.

 

[Nige]

I feel good that at least I know why the seal I was originally replacing had wear on its metal casing since it was lightly making contact with the bearing. Not a good thing at all.

If you recall I did mention at the time that the seal might be a symptom not the root cause of the problem. You just confirmed it.

Does anyone have a lead on good parts dealers for CAT parts?

Have you tried Offroad Equipment in Alcoa TN.?

 

[surferboy120]

If you recall I did mention at the time that the seal might be a symptom not the root cause of the problem. You just confirmed it.


Have you tried Offroad Equipment in Alcoa TN.?

You were certainly correct and I believe the shimming is the culprit. Luckily the damage is super minor given the seal gave up first and I jumped on it. Everything else looks perfect thankfully.

Thank you Nige on the tip to try Offroad Equipment I will be giving them a call now. Fingers crossed they have the shim stack.

 

[Nige]

Thank you Nige on the tip to try Offroad Equipment I will be giving them a call now.

From what has been posted on this forum ORE are extremely good over the phone. If they can't help maybe ask them to recommend any other possibilities.?

 

[surferboy120]

I was able to source the shim pack working with my local CAT dealer and their dealer network found one up North so its on its way. I had no luck otherwise but.... they did say Puerto Rico does have them but getting them would have been more $.

Nige I did check Offroad Equipment but they didnt have it either but thank you for sharing the recommendation.

 

[surferboy120]

Now I am off to research how I am supposed to determine the shim pack tolerances to prevent the seal and bearing from making contact again. If anyone has the skinny on this I am all ears.

 

[Nige]

Now I am off to research how I am supposed to determine the shim pack tolerances to prevent the seal and bearing from making contact again. If anyone has the skinny on this I am all ears.

I thought you had a service manual.?
Here is the procedure for the Transfer Gears on a 3F/3R transmission.

 

[pittsburgh cat man]

Cat for the most part sets shim packs with a dial indicator spec should tell you the movement they want you start with full pack and remove shims till you get to spec also do this without a seal on the cage

 

[surferboy120]

I thought you had a service manual.?
Here is the procedure for the Transfer Gears on a 3F/3R transmission.

Thank you and yes I have the paperback and the electronic updated version now. I just hadnt gone through to see the procedure if any is recommended. Sounds like a good idea Pittsburgh Cat Man has for shimming correctly..

 

[surferboy120]

Cat for the most part sets shim packs with a dial indicator spec should tell you the movement they want you start with full pack and remove shims till you get to spec also do this without a seal on the cage

Thank you I appreciate the information on shimming!

 

[pittsburgh cat man]

remember to push gear into case zero indicator a lady slipper will prob help you push gear towards cage. I never liked the method of measureing distance between case and cage always seemed to be a pain to get the gap even

 

[surferboy120]

Update:

My 931B is up and running leak free! I wanted to say thank you to all that provided not only information but guidance through this process. I have run the machine for 4 hours now and its doing what it should be.

It may be old but it really runs well and is a HUGE help.

Again BIG Thank you!

 

[Welder Dave]

You should be glad it's older because you were able to fix it yourself.

 

[surferboy120]

You should be glad it's older because you were able to fix it yourself.

I totally agree with that. I am super grateful. This machine is perfect for my needs.

 

[Welder Dave]

931B's are good machines when they work properly.