D20 output shaft preload issue

73azbronco · Jun 8, 2010

Well, three months into the D20 and now I'm ready to put it back together, at this rate I should be on the road by Aug, 2029. Life keeps getting in the way.

This question revolves around the output shaft bearing preload, I have the "larger" bearing as recommmended to check shim/output endplay, I also found some NOS spicer yokes as mine were chewed up. Test fitting the yokes I note the yoke won't slip onto the shaft, I'm guessing this means light hammering to get it to go on until the non locking bolt can take it to torque, correct?

Next question, my guess is since I need to malletize the yoke on, I will need to tap the shaft out of it when done to use the real bearing and install the seal, any problems driving the shaft out with a drift, no damage to bearing?

By the way, the yokes are Spicer # 2-4-4061x and they come with dirt shields.

70_Steve · Jun 8, 2010

73azbronco said:
Test fitting the yokes I note the yoke won't slip onto the shaft, I'm guessing this means light hammering to get it to go on until the non locking bolt can take it to torque, correct?

I've been playing with my transfer case the last week or so. I found that the front yoke didn't want to slide right on, so a couple taps with a rawhide or plastic mallet was enough to get it moving.

73azbronco said:
Next question, my guess is since I need to malletize the yoke on, I will need to tap the shaft out of it when done to use the real bearing and install the seal, any problems driving the shaft out with a drift, no damage to bearing?

You could do that or just use a puller to get it to slide off.

BTW, I wasn't sure how much preload I should have on those rear output shaft bearings so I set the end play at 0.000. I had initially measured the end play at 0.012, so I removed 0.012 shims.

Viperwolf1 · Jun 8, 2010

Sometimes the ends of the shaft splines get burred up. I take a small file and clean them up so the yoke slides on easily. I don't see a problem using a soft hammer to tap it on and off but it shouldn't take much. Don't beat on the threaded portion of the output shaft without a nut on it.

73azbronco · Jun 9, 2010

Ford factory book says preload should be set to .003-.005".

I've triple checked for burs and don't see any, tried the old yoke and it won't slip on either, I'll try the soft mallet method.

Watch out beating the nut on the shaft, I stripped the nut out ding that once, good thing the shaft threads were tougher than the nut. I was just going to use a drift on the cneter part of the shaft. take care.

70_Steve · Jun 9, 2010

73azbronco said:
Ford factory book says preload should be set to .003-.005".

Not preload... Endplay! That's what the book says.

But several here have noted they've "fixed" the problem with popping out of gear by eliminating the endplay, and put the bearings under preload.

I've had problems with my t-case popping out of rear low ever since I rebuilt it. I "thought" I did a good job of setting the endplay of the rear output shaft to spec. But, when I pulled it last week and checked it, there was 0.012 end play. And you could see the shaft wobble back and forth. No wonder the gears wouldn't stay aligned.

So, I have eliminated the endplay, but not exactly put the bearings under preload. I'll see how that works. And if it doesn't work, what's another $350 in new gears...

Bronchole · Jun 9, 2010

70_Steve said:
Not preload... Endplay! That's what the book says.

I seem to remember the book saying preload also. Can someone post a pick/link for thoes looking at this thread in the future?

70_Steve · Jun 9, 2010

Bronchole said:
Can someone post a pick/link for thoes looking at this thread in the future?

Last page.
http://www.classicbroncos.com/dana20/dana_20_manual.html

73azbronco · Jun 9, 2010

My bad it is endplay. When you pulled it and it was .012, do you remember what you set it to during install? I am trying the technique via i think Viperwolf of using an 18 bearing instead of 17 and also leaving out the seal until endplay is set. Did you do those things? Lastly, did you press the bearings in or do the heat/cool method and did you torque it up to 150ft/lbs??

I am looking at the spacers pulled from the origianl build and they look smooshed on one side as in they were torqued pretty well.

70_Steve · Jun 9, 2010

73azbronco said:
My bad it is endplay. When you pulled it and it was .012, do you remember what you set it to during install? I am trying the technique via i think Viperwolf of using an 18 bearing instead of 17 and also leaving out the seal until endplay is set. Did you do those things? Lastly, did you press the bearings in or do the heat/cool method and did you torque it up to 150ft/lbs??

I am looking at the spacers pulled from the original build and they look smooshed on one side as in they were torqued pretty well.

I had intended, and thought I did, set the endplay to .005, but I think where I f'd up was I didn't torque the yoke nut when I checked the end play. Just kinda snugged it up. Plus I used the original shims, as new shims were not included in the rebuild kit. Also, the rear bearing in the rebuild kit I got 5-6-7 years ago, when I did this, is a slip fit on the shaft!!! Sorry, didn't think to get the number off it when I just had it apart. I really don't think it matters if it's an interference fit or not, since having the yoke torque on top of it (as well as the speedometer drive gear) will pretty much keep it from spinning!

When I rebuilt my friends t-case a month or so ago, I just heated the bearings up in my toaster oven to 300 for about 10 minutes, and they dropped right on.

NC-Fordguy · Jun 9, 2010

I just installed a wild horses rear output shaft on my 20.

The procedure I used to set end play according to the instructions from wild horses was in the manner:

Setting the housing in a bench vice and leaving the oil ring out, torque the yoke nut to 125 foot pounds. Then using an INCH pound torque wrench turn the yoke nut. When the shaft starts to move the reading should be in between 2-7 INCH pounds. Adjust shim count accordingly if it doesn't meet spec.

Once the spec is reached, install oil ring and torque yoke nut to 150 foot pounds and then install into case.

I've put about 400 miles on my bronco since the install and all seems to be working fine

Bronchole · Jun 9, 2010

NC-Fordguy said:
I just installed a wild horses rear output shaft on my 20.

The procedure I used to set end play according to the instructions from wild horses was in the manner:

Setting the housing in a bench vice and leaving the oil ring out, torque the yoke nut to 125 foot pounds. Then using an INCH pound torque wrench turn the yoke nut. When the shaft starts to move the reading should be in between 2-7 INCH pounds. Adjust shim count accordingly if it doesn't meet spec.

Once the spec is reached, install oil ring and torque yoke nut to 150 foot pounds and then install into case.

I've put about 400 miles on my bronco since the install and all seems to be working fine

That explains why I thought it was supposed to be preloaded. I was installing the WH output shaft also. I thought I was following the normal rebuild data though. I guess I was following the WD data.

NC-Fordguy · Jun 9, 2010

Looking at my post I neglected to state to install the yoke too;D

The shims go inbetween the speedo gear and the larger bearing. IIRC I used 12 thousandths worth of shims to get it right, which neccesitated pulling the speedo gear a couple of times.

Hopefully you have an INCH pound torque wrench handy

Hope this helps you out

73azbronco · Jun 14, 2010

Actually the Ford manual shows the shims on the small bearing side so you don't have to remove the gear each time, at least thats how mine came apart, shims on small bearing side.

Here is the WH extreme instructions showing shims on big bearing side, not what ford shows:
http://www.wildhorses4x4.com/downloads/8272 08-08-06.pdf

Here is the Ford manual showing shims aft of speedo or toward rear of truck on small bearing side (scroll down to ford d20 pic):
http://www.google.com/imgres?imgurl...a=X&ei=4tIVTIedHNOFnwe2_LWnDg&ved=0CBQQ9QEwAA

Not enough hours in the day, setup the bearing using the larger bearing per Viper today, I ground down the old race to press the new small bearing race in. I will finish tomorrow and give an endplay-inch pound answer then.

73azbronco · Jun 14, 2010

Rear Output assembly done.

Endplay set to .0005-.001. No inch lbs of resistance. Feels great, no clunking when moved.

Info you all, with it set to .005, it felt just way too lose, it clunk around. I would have liked 1-2 thou but the shims provided didn't let me set that, they come in .005, .010, 015 thickness, sorta hard to get zeroed with those shims... with that I still ended up shaving some using emory paper.

Smaller "setup bearing" is the only way to do this, it took 8 attemptes to full torque to zero it in, good news is my new yoke slips right off and on easily.

WH has their extreme setup set by in-lb force, I'm not to sure thats the best way, because, how fast do you turn the wrench to get inch-lb reading? slow? fast? It all depends.

Well let you know how this lasts. Insides together tommorrow.

73azbronco · Jun 15, 2010

Question for Viperwolf or 70steve, on the front output shaft, if I'm reading this manual right, I need to press the rear bearing onto the front output shaft, install the shaft, then install the front bearing and race, once done the shaft is stuck in there. Then install the "front" plate minus seal, then setup endplay by adjusting the "rear" bearing cup via shims? Once set, then remove front plate, install seal and reinstall again?

Question on the "front" front output shaft bearing race, just install until flush with case as front plate will hol it, right?

I noted your use of copper seal on the shims which is how I'll do it. Did you use any additional seal on the other gaskets? I know it needs sealant on all the bolts as they penetrate the case, what did you use? Locktight blue? RTV? Both?

Thanks, one day at a time.

Viperwolf1 · Jun 15, 2010

Order looks correct. No need to leave the front seal out when assembling, just put it all together the first time. Don't forget the gear and the spacer. If it's a T-shift it has a snap ring.

The front retainer sets the spacing for the front bearing cup so that leaves the only possible adjustment at the back with the shims. I like to use High-Tack for the shims and gaskets and teflon thread sealant on the bolts.

70_Steve · Jun 15, 2010

73azbronco said:
Then install the "front" plate minus seal, then setup endplay by adjusting the "rear" bearing cup via shims? Once set, then remove front plate, install seal and reinstall again?

Question on the "front" front output shaft bearing race, just install until flush with case as front plate will hol it, right?

I noted your use of copper seal on the shims which is how I'll do it. Did you use any additional seal on the other gaskets? I know it needs sealant on all the bolts as they penetrate the case, what did you use? Locktight blue? RTV? Both?

As Viperwolf1 says, just go ahead and install the seal. That front retainer will only get installed one time. All the shiming of the end play is done from the rear.

Here's a pic of where the front race wound up in mine, but understand that when shiming, you're forcing everything up against the front retainer. So, just go ahead and install the front race wherever (maybe a little shallower than mine) install the front retainer to set the position of the front race, and start shimming from the rear.You may want to use a rawhide mallet and tap the rear race into the case just a little before setting the end play, just to make sure the races, bearings, etc are tight up against the front retainer.

Viperwolf1 says he has good luck with HiTack spray, and I've had good luck with Coppercoat. I'm just getting ready to set mine up again, and may go ahead and try the HiTack spray. Either way, I think the important thing is to get "something" on each shim, but not enough to affect the end play. I set one up maybe two months ago and measured the difference in end play before and after the coppercoat spray. Best I could measure with my cheap HF dial indicator was maybe .0005 change after assembly with coppercoat.

I usually use #2 Permatex for bolt threads.

73azbronco · Jun 16, 2010

Couple more front output questions/J shift

Since mine is a J shift, I didn't have the snap ring on the front output shaft. Worse, since it's been two onths sinse teardown

, need some assurance I'm putting this back right because my diagrams are for a T shift.

I have two washer/spacers, one large, one small.

The larger one has the reverse writing of "made in the USA" and wear mark which fits against the front gear and backside of front bearing. The small spacer/washer only fits onto the front shaft to the end of the splines, the old bearing has a wear mark which matches this, so the small spacer fits between the bearing and the yoke, and stops the yoke from bottoming?

Here is a pic with the way i think they should go, minus the bearing which would be between them, correct? This means the small ring then actually sets the front bearing depth for installation?

70_Steve · Jun 16, 2010

73azbronco said:
so the small spacer fits between the bearing and the yoke, and stops the yoke from bottoming?

Here is a pic with the way i think they should go, minus the bearing which would be between them, correct? This means the small ring then actually sets the front bearing depth for installation?

Yes, that's how they go back together. I dunno if I'd go so far as saying the small spacer set the front bearing depth. If the front bearing is installed correctly, it will be tight to the large spacer, which is tight to the gear, which is tight to the rear end of the shaft. That pretty much sets the position of the front bearing. What I see is that the small spacer gives the yoke something solid to tighten up against. That's why I made a similar spacer for my t-shift.

73azbronco · Jun 16, 2010

70_Steve said:
Yes, that's how they go back together. I dunno if I'd go so far as saying the small spacer set the front bearing depth. If the front bearing is installed correctly, it will be tight to the large spacer, which is tight to the gear, which is tight to the rear end of the shaft. That pretty much sets the position of the front bearing. What I see is that the small spacer gives the yoke something solid to tighten up against. That's why I made a similar spacer for my t-shift.

So your saying the small spacer is only for the yoke and the bearing should press fit tight to the gear with the large spacer in betwee, got it. Good to know as I was going to drive the bearing in until the spacer bottomed, that would have sucked...I think. thanks again.

D20 output shaft preload issue

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