2wd to 4wd transmission

Fless said:

With the mods you have it might be good to specify which year/model tranny is broken, and the year and model of the potential donor.

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Trey Hardy said:

@NickTransmissions
I need some help here man
Like the title says


my ammco transmission is less then 6 months old and less then 10,000 miles on it


last Wednesday otw home from work I hit the highway around 75 or so and felt a terrible vibration when I let off the gas the tail shaft housing exploded on me and it took a chunk of the transmission case with it…


Ammco isn’t wanting to warranty it either which is a real kick in the balls their blaming the driveshaft angle that caused the issue


I got a parts avalanche but it’s 4wd will a 2wd trail shaft housing bolt right up or would I have to tear down the 4wd transmission to swap the output shaft for a 2wd one?


or will the aluminum 2wd driveshaft be short enough to work on the 4wd transmission?


or would I have to swap the steel driveshaft out of the avalanche to work on the transmission?


looking for the easiest solution here I don’t have another 3600$ to put into a transmission





if I do have to tear into the trans I thought to rob the new parts out of the Ammco transmission as long as they ain’t completely fcked but hopefully they ain’t but idk until I get torn into it…
View attachment 437467View attachment 437468View attachment 437469
Ps that bolt is missing cause of the chunk taken out of the transmission case..

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NickTransmissions said:

Ouch!

While I'm no fan of AAMCO overall, they are likely correct here as nothing inside the transmission (unless a literal explosion occurred for some reason) would cause the damage shown in the pics. Definitely have your pinion angles checked, look over the suspension carefully for worn/non-serviceable parts, etc.

Unfortunately, there is no 'easy' solution to this problem. To convert a 4WD transmission to a 2WD transmission, you'd have to disassemble the 4X4 unit to swap the shafts...The output shaft is secured in the mid-case by a snap ring at the front planetary carrier.

Or you can gamble on a good-used unit but it's a gamble and may not last very long which would put you back to square one...

Lastly, you can simply take your existing transmission out, tear it down and inspect it following my various videos on 4L60E tear downs then rebuild the transmission with a replacement 2WD output shaft and extension housing. Of all your options, that's the route I'd take - perhaps pair it with buying a used trans to get you buy for a few months or so. This way, you're not under the gun, trying to learn a new trade while having to get the vehicle back on the road.

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Trey Hardy said:

I thought to swap that 4wd trans I got and just leave the transfer case un hooked would work but I think the driveshaft length would become a issue then

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Trey Hardy said:

I thought to swap that 4wd trans I got and just leave the transfer case un hooked would work but I think the driveshaft length would become a issue then

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