4x4 end play

[JDPlowboy]

Since I can't find a thread on the subject, figured I'd start a new one for future 4x4 housing swap references. Truck recently had a new extension housing installed. A few hundred miles later the truck quits moving on its own. Dis assembled trans and found the rear thrust bearing between output shaft and sun gear was destroyed. So I'm
Guessing the rear end play changed with the new extension housing. There is a shim between the spacer collar and rear bearing. I was told they have 1, 2 or 3 holes in them to specify thickness.

I had to replace p3, sun gear and output shaft. Re used the same 2 hole washer and I can't get any end play out of the output shaft. Does anyone have any experience with this?

 

[JDPlowboy]

Since you tighten the output shaft to the rear bearing, I'm guessing one would have to take an H gauge and get measurements from extension housing down to output shaft then measurement from rear of case down to thrust bearing and figure the clearance?

 

[JDPlowboy]

This is what I came up with

Trans is on a stand with tailhousing up so the planetary gears are resting on the c3 backing plate.

Then I backed the spanner nut off so the output shaft can float freely between rear thrust washer and rear housing bearing. Zero'd the mic with the shaft sitting down on the thrust bearing then I'm prying up on the spanner nut so it pulls the shaft up to the rear housing bearing. The end play is measured at .022". Atsg manual calls for .018-0.32" so I'm calling this a satisfactory measurement.

 

[Mike L.]

There will never be play at the output shaft once the rear nut is tightened. End play is checked at the input shaft. The selective washer at the rear will determine what your end play will be.

 

[JDPlowboy]

There will never be play at the output shaft once the rear nut is tightened. End play is checked at the input shaft. The selective washer at the rear will determine what your end play will be.

When you pull up on the input shaft your just lifting the c1/c2 clutch housing out of the p1 planetary right? Or would you check endplay on input shaft with tailhousing up and be pushing in on Input shaft?

 

[THEFERMANATOR]

Sounds like the extension housing was changed without pulling the trans. This is a common outcome when you do them without pulling the trans, and it almost always ends up like this. Many still swap them in the truck to try and save the labor, and then this happens. Without pulling the trans, you can't verify the clearances, or be certain that the thrust washer doesn't drop down.

 

[Mike L.]

When you pull up on the input shaft your just lifting the c1/c2 clutch housing out of the p1 planetary right? Or would you check endplay on input shaft with tailhousing up and be pushing in on Input shaft?

Why do you not believe me? You are pissing in the wind doing what you're doing.

 

[PureHybrid]

When you pull up on the input shaft your just lifting the c1/c2 clutch housing out of the p1 planetary right? Or would you check endplay on input shaft with tailhousing up and be pushing in on Input shaft?

The planetary gears "float" inside the trans so to speak.

 

[JDPlowboy]

Why do you not believe me? You are pissing in the wind doing what you're doing.

If there's anyone out there I'd believe over anyone else it would be you.

Just wasn't sure how checking the input end play assures that the rear thrust is ok. I don't wanna just replace parts and say it's fixed. was hoping to find a sure sign as to why it failed.

Truck was a low on trans oil but still on stick. Metal in the pan, dropped trans, rear thrust bearing was gone. Trim valve a and b were stuck. Pump looks good, clutches and clearances are all good. Cleaned everything and got it back together and on then road. Just wanted to make sure the endplay wasn't too loose or too tight

 

[Chevy1925]

If there's anyone out there I'd believe over anyone else it would be you.

Just wasn't sure how checking the input end play assures that the rear thrust is ok. I don't wanna just replace parts and say it's fixed. was hoping to find a sure sign as to why it failed.

Truck was a low on trans oil but still on stick. Metal in the pan, dropped trans, rear thrust bearing was gone. Trim valve a and b were stuck. Pump looks good, clutches and clearances are all good. Cleaned everything and got it back together and on then road. Just wanted to make sure the endplay wasn't too loose or too tight

it was due to who ever replaced the tail shaft housing and not pulling the trans, tipping onto bellhousing, and then replacing it.

 

[JDPlowboy]

it was due to who ever replaced the tail shaft housing and not pulling the trans, tipping onto bellhousing, and then replacing it.

It got a new housing when it got built so it was installed on a stand.

 

[Chevy1925]

It got a new housing when it got built so it was installed on a stand.

Ah I was under the impression it was changed in the truck from your first post

 

[THEFERMANATOR]

Ah I was under the impression it was changed in the truck from your first post

I was as well.

 

[Mike L.]

Me thinks a Torrington might have been installed upside down.

 

[JDPlowboy]

Me thinks a Torrington might have been installed upside down.

Not saying that's impossible but shouldn't it have failed sooner than 1000 miles?

 

[Mike L.]

Not saying that's impossible but shouldn't it have failed sooner than 1000 miles?

No, I've seen them go much longer.

 

[JDPlowboy]

I see

 

[THEFERMANATOR]

It takes time for things to chew up in there when something is put in wrong. I followed the wrong part of the ATSG manual and put the one torrington in upside down(my gut said it was upside down, but I followed the book). 30K miles later I pulled it out and it was only slightly scored inside of it.

 

[JDPlowboy]

Ya the rear thrust tho is one that has a collar and if it was upside down the collar would be supporting the shaft instead of the bearing surface. Now that this one is correctly assembled it shouldn't have anymore problems

 

[WolfLMM]

It takes time for things to chew up in there when something is put in wrong. I followed the wrong part of the ATSG manual and put the one torrington in upside down(my gut said it was upside down, but I followed the book). 30K miles later I pulled it out and it was only slightly scored inside of it.

It's been a long time, but I remember one being upside from the factory on my 01. Don't remember which one it was but had 150,000 on the truck, never been in trans. I called Mike and told him how it came out, wondering if I some how flipped by mistake, he told me the correct way to install it. No problems either way.