T/C bearing preload shims

Cacti_Ken · Post by **Cacti_Ken** » Sun Aug 29, 2010 8:08 pm

You know those shims on the rear output bearing before the speedometer housing goes on to preload the bearing. The shims have to be very clean to get the right preload onthe bearing.
Question, how to keep oil from seeping thru them without putting any sealant on them. if any sealant is used on the shims then that defeats their purpose.

TomM · Post by **TomM** » Mon Aug 30, 2010 5:58 am

Ken,
Great question and one that is probably debatable.
Removed original shims never show signs of having had any sealant. On my rebuilds cleaned shims have tendency to weep. On the most recent rebuild (M38) I sprayed a very, very thin coat of spray hi-tack sealant between shims (almost just overspray was the amount). Rick Grovers site may even have a guideline for allowance of shim thickness with sealant.
With the bolts torqued properly the play was to spec and over time there have been no leaks.
Could the thickness of the pack have changed due to the sealant changing? Probably yes; but thats where keeping the amount of sealant to the barest minimum comes in.
Tom

Cacti_Ken · Post by **Cacti_Ken** » Mon Aug 30, 2010 6:37 am

Thanks Tom,

Guess I'll have to do it over.

Cacti_Ken · Post by **Cacti_Ken** » Mon Aug 30, 2010 8:10 pm

Well, the shims aren't leaking. The darn seal is. I just replaced it a few weeks ago.

I don't know whats going but I'm gonna get another companion flange

Post by **wesk** » Mon Aug 30, 2010 8:37 pm

Does the companion flange have a groove worn in it where the seal lip rests?

Did you apply RTV to the shaft splines during assembly?

TomM · Post by **TomM** » Tue Aug 31, 2010 6:34 am

Price a speedi sleeve for your companion flange also. Sometimes they are cheap and other places sell them at the same price as an entire new flange.
On your seal replacement, did you put sealant on the outside edge of the seal before you drove it in? Also after installing the flange and before installing the washer and nut you should put a little sealant around the spline to flange area to keep it from leaking around the nut.

Before you replace too much, did you hose the entire area down with brake cleaner so you can look for a drop to give you a telltale where the leak is?

Tom

Cacti_Ken · Post by **Cacti_Ken** » Tue Aug 31, 2010 7:56 am

wesk wrote:Does the companion flange have a groove worn in it where the seal lip rests?

Did you apply RTV to the shaft splines during assembly?

No the flange is smooth all the way. and measures the same OD from one end to the other. 1.552"

Yes I did use RTV in the splines. There wasn't any oil coming from the washer and nut area.

Cacti_Ken · Post by **Cacti_Ken** » Tue Aug 31, 2010 8:03 am

TomM wrote:Price a speedi sleeve for your companion flange also. Sometimes they are cheap and other places sell them at the same price as an entire new flange.
On your seal replacement, did you put sealant on the outside edge of the seal before you drove it in? Also after installing the flange and before installing the washer and nut you should put a little sealant around the spline to flange area to keep it from leaking around the nut.

Before you replace too much, did you hose the entire area down with brake cleaner so you can look for a drop to give you a telltale where the leak is?

Tom

I used the paper gasket before pushing the seal in. I didn't figure that I needed to put any sealant around the seal housing before installing since I put the gasket it.

I disassembled the brakes shoes and the backing plate and removed the speedometer housing and took it to the bench to work on.

Yes I washed the oil off everything and it was clean and dry.

The brake shoes are all oily now.

Post by **wesk** » Tue Aug 31, 2010 12:17 pm

Ken,
From your descriptions there is nothing wrong with your yoke.

Was the yoke seated tight? Meaning no play forward aft on the spline shaft.

Ken, Can you tell us exactly which components in the photo had oil on them?

Cacti_Ken · Post by **Cacti_Ken** » Wed Sep 01, 2010 12:33 am

Wes, I have the M38 setup. But everything inside the brake drum was oily, nothing on the out side. And as I said in the previous post the nut was dry. I don't have a torq wrench. I used my air impack driver to set the nut. What do you think, could that be where I'm screwing up.

Post by **wesk** » Wed Sep 01, 2010 1:07 am

Have you been able to nail down exactly where the leak starts from? If not you may have to remove all the brake parts and clean her up and run it a bit with the brake removed so you can ascertain the real leak.

I would not think the impact wrench would cause the leak.

Cacti_Ken · Post by **Cacti_Ken** » Wed Sep 01, 2010 1:18 am

Man! you can't sleep either?

I understand what you are saying. There definately no oil on the nut side. All I can do is put another seal in and give another try and leave the brake stuff off this time. I figured seting that nut with the impact wrench was enough to get it tight.

I'll go rent a torq wrench tomorrow and see how it compares to the impack wrench.

Post by **wesk** » Wed Sep 01, 2010 2:01 am

I've always just used the impact wrench with no problems.

You're sure both output shaft bearings are good?

Cacti_Ken · Post by **Cacti_Ken** » Wed Sep 01, 2010 2:33 am

Well, I rebuilt the case with all new components less than a few thousand miles ago. I haven't checked the odometer but I would guess I haven't put 3 thousand miles on it yet. I guess they could have worn if the preload was too tight. I took pains to make sure that was in tolerance though. I did have a concern when I drained the oil to find what I thought was excessive silver color in the oil.

Cacti_Ken · Post by **Cacti_Ken** » Wed Sep 01, 2010 2:50 am

I feel a transfercase removal for inspection coming. I'm gonna check the end play first.

T/C bearing preload shims

T/C bearing preload shims

sealant

leaks

Re: leaks