Leaking Transfer Case - Best Kits for Repair

[The FLU farm]

...so basically the tcase overflow vent is for exactly just that...

Well, not quite. Just like with the engine, trans, and axles, there's a vent to allow for expansion and contraction of the fluids and air inside. Without those vents we'd be changing a lot ​of seals, and often.

 

[cucvrus]

ok, interesting, so basically the tcase overflow vent is for exactly just that-that is a leaking transmission seal (output shaft seal)...bc yes-how can one fill too much in tcase if using the fill hole as I can't imagine they use the overflow vent to fill it

That is not an over flow vent. It is just a vent/breather to allow excess gasses/pressure to vent as the fluids/oil gets hot and expands. I don't think the leaking rear seal was the designed intent for the breather on the transfer case. I feel if it gets to that point of leaking it is stressing other seals on the transfer case also. I have extended the breather on Terminus M1009 and a few other CUCV's I own. I run in water up to the brake pedal at times and that would be above the vent inlet. Have a great day.

 

[BradL84D30M1008]

I'm doing the same thing......had my driveshaft re-tubed, balanced, and both u joints replaced (Spicer part # U5-799, 1350 series) today......new u joint straps/bolts and pinion yoke ordered and due to arrive shortly.

It was amazing once I had the driveshaft out of the truck and in clear light at the shop to be able to see how dinged the driveshaft was in several places, and yes with a slight bend to it.......forklift gremlins?

Of course it was no wonder that I had a horrible vibration at 40-45 mph. Now that I have a "new" driveshaft freshly painted, almost hate to put it back under the truck it looks so good.

Now if I can just get my replacement TH400/NP208 adapter to arrive, I can proceed to address the transmission fluid leak.....what a deal!



new

I just had a driveshaft rebuilt this week for Terminus M1009. That was both U joints balanced and all $169.70. That sort of takes the guess work out of it. I heard the squeaking Saturday at RC and was surprised to find both U joints bad. The yoke I replaced with a Yukon yoke from Autozone. I marked the nut and pinion. I removed the nut with a breaker bar and counted the revolutions that I turned it to remove it , replaced the seal and yoke and tightened the nut back up to the same point again. Checked it with the breaker bar and it was tight. Good enough. If you go crazy with the impact I am sure you could do damage. But just use common sense and you will be good. If I am wrong. Sorry It worked for me many times. And I learned it from old timers. Have a Great DAY.

 

[BradL84D30M1008]

What size socket is required for nut removal on the pinion yoke?

I just had a driveshaft rebuilt this week for Terminus M1009. That was both U joints balanced and all $169.70. That sort of takes the guess work out of it. I heard the squeaking Saturday at RC and was surprised to find both U joints bad. The yoke I replaced with a Yukon yoke from Autozone. I marked the nut and pinion. I removed the nut with a breaker bar and counted the revolutions that I turned it to remove it , replaced the seal and yoke and tightened the nut back up to the same point again. Checked it with the breaker bar and it was tight. Good enough. If you go crazy with the impact I am sure you could do damage. But just use common sense and you will be good. If I am wrong. Sorry It worked for me many times. And I learned it from old timers. Have a Great DAY.

 

[cucvrus]

M1009 stock rear is 1 1/4" pinion yoke nut. Use an electric/air impact socket. Mark the socket hit the trigger slowly and count the revolutions to remove. Put the nut back on the same way and you will be good. NOT 100% perfect. But good enough. It has worked for me. If you go wild tightening the nut you will crush the pinion bearing/sleeve. I had barbed wire wrapped in my M1009 pinion yoke last year and changed it out and have been running it ever since. It was time to change it anyway. It had 125K on it. Good as new.

 

[BradL84D30M1008]

My M1028 stock rear must be 1 1/2" pinion yoke nut, 1 1/4" socket not even close to covering that big nut! Had a 36MM socket handy and it was just a bit small.

M1009 stock rear is 1 1/4" pinion yoke nut. Use an electric/air impact socket. Mark the socket hit the trigger slowly and count the revolutions to remove. Put the nut back on the same way and you will be good. NOT 100% perfect. But good enough. It has worked for me. If you go wild tightening the nut you will crush the pinion bearing/sleeve. I had barbed wire wrapped in my M1009 pinion yoke last year and changed it out and have been running it ever since. It was time to change it anyway. It had 125K on it. Good as new.

 

[cucvrus]

OK since you used my paragraph in the quote M1009 Terminus I answered the question based on an M1009. I will check the 14 Bolt in a few minutes. BRB.

 

[cucvrus]

I am thinking 1 1/2" possibly 1 7/16" maybe 38 MM but I think the 1 1/2" will do the job. Good Luck. I am still working on the issue.

 

[BradL84D30M1008]

Thanks......found some good useful info via pirate4X4.com which indicates pinion nut size is 1.5" for my GM 10.5 " 14 bolt in my M1028.

My question is how in the heck do you get the pinion nut off, and then back on......up to 300+ ft/lbs torque is crazy tight......not sure I could budge that on my best day 20 years ago!

Did you re-use your old pinion nut, or install a new one?

I am thinking 1 1/2" possibly 1 7/16" maybe 38 MM but I think the 1 1/2" will do the job. Good Luck. I am still working on the issue.

 

[Chaski]

You use a BIG breaker bar... and a good way to hold the yoke. Should also get a beam or dial type inch pound torque wrench for measuring preload.

There are other ways to change the pinion seal, but a before and after with a dial type inch pound is best, especially if you are swapping parts. It is the only way to measure preload. Suggested tools below.

 

[computer54]

I got a transfercase rebuild kit (complete kit) for my truck from Rockauto so check there, because the loco auto parts store did not have them in stock aor could not get them for me.

 

[BradL84D30M1008]

Verified part of the reason I had issues with the rear u-joint sliding in the straps/yoke and contributing to rear end vibration was the OEM yoke was 1/16" wider than the Yukon yoke I replaced it with today......I notice the new Yukon straps are not exactly formed yet to the new u-joint.....anybody know if that's an issue?

View attachment 683368 View attachment 683369View attachment 683370

 

[The FLU farm]

Huh? If I understand this correctly, you must've had the wrong size U-joint in the OE yoke.
The attachments don't work, but when you say that the aftermarket straps "are not exactly formed yet to the new U-joint" it sounds like you still have a mismatch.
I've never had an application where the straps were supposed to form to the U-joint. I always thought that things were supposed to fit, or something is wrong.

 

[BradL84D30M1008]

Yoke, bolts, and straps all Yukon parts

 

[BradL84D30M1008]

Spicer 1350 series u-joint, U5-799.

I think OEM yoke was abused due to bent drive shift vibrating horribly in the yoke. I've since had the driveshaft re-tubed and balanced.

 

[The FLU farm]

I can't see the tab for the cup in the second photo, so it's hard to tell what the real widths of those yokes are.
And it would take an awful lot of abuse to tweak a yoke, even if banging it against rocks. Having a U-joint let go is the only way I can remember seeing a yoke get damaged. But it would be simple enough to check its straightness, or lack thereof.

 

[BradL84D30M1008]

The Yukon yoke didn't have outside tabs like the OEM to retain the u-joint caps......on the Yukon the space for the caps is recessed into the yoke itself.......very form fitting to the exact width of the 3.625" width of the spicer 1350 u-joint

I can't see the tab for the cup in the second photo, so it's hard to tell what the real widths of those yokes are.
And it would take an awful lot of abuse to tweak a yoke, even if banging it against rocks. Having a U-joint let go is the only way I can remember seeing a yoke get damaged. But it would be simple enough to check its straightness, or lack thereof.

 

[cucvrus]

Looks great. It is great that the u joint is tight in the yoke and you have no slop. Regardless of how the slop got there it was there and you fixed it. Great job. I hope it runs smooth now. You put a lot of time and money into that drive line. Have a great day and enjoy the CUCV.

 

[BradL84D30M1008]

Yukon strap part # is YY STR-007.......supposed to fit Spicer 1350 u-joint with 1.188" cap diameter

 

[BradL84D30M1008]

Thanks for your advice and assistance cucvrus......should have the replacement TH400/NP208 adapter installed in a couple weeks

Looks great. It is great that the u joint is tight in the yoke and you have no slop. Regardless of how the slop got there it was there and you fixed it. Great job. I hope it runs smooth now. You put a lot of time and money into that drive line. Have a great day and enjoy the CUCV.