2wd to 4wd transmission

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Trey Hardy

8” fabtech icon coilovers uniballs 24x14on35/15.50
Joined
Jun 12, 2020
Posts
3,326
Reaction score
8,855
Location
Eastern North Carolina
@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 wensday 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…
RenderedImage.jpegIMG_9744.jpegIMG_9743.jpeg
Ps that bolt is missing cause of the chunk taken out of the transmission case..
 
Last edited:

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
11,854
Reaction score
24,111
Location
Elev 5,280
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.
 

petethepug

Michael
Joined
May 4, 2016
Posts
3,009
Reaction score
3,259
Location
SoCal
Wait? Aamco trans is toast. They replaced and installed a new trans without giving you a “hold harmless” notification that you’re paying for a warranty trans, but we may change our mind on honoring the warranty because it doesn’t suit us?

Your paperwork from Aamco is a very powerful contract. Ask them to give an explanation of why they won’t warranty it on a COPY of you bill because the BBB wants it.

As soon as you have that you’ve got bad faith and you’re no longer obligated to have them fix it. Either call an Atty or local automotive bureau.
 
Last edited:

randeez

Full Access Member
Joined
Sep 29, 2017
Posts
7,444
Reaction score
23,678
Location
south florida
would need to swap the transmission and transfer case, the 4wd tailshaft is already short. just leave the transfer case in 2wd.
not sure with that much lift you would have a driveshaft that would work
 

NickTransmissions

Sin City
Supporting Member
Joined
Mar 9, 2023
Posts
1,088
Reaction score
2,613
Location
The transmission bench
@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..
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.
 
OP
OP
Trey Hardy

Trey Hardy

8” fabtech icon coilovers uniballs 24x14on35/15.50
Joined
Jun 12, 2020
Posts
3,326
Reaction score
8,855
Location
Eastern North Carolina
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.
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
 

randeez

Full Access Member
Joined
Sep 29, 2017
Posts
7,444
Reaction score
23,678
Location
south florida
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
2wd tailshaft is longer to get out of the tail housing

a 4wd tailshaft is short cause it splines right into the transfer case
 

NickTransmissions

Sin City
Supporting Member
Joined
Mar 9, 2023
Posts
1,088
Reaction score
2,613
Location
The transmission bench
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
Do you have a 2WD or 4WD truck?

If you have a 2WD, what are you mentioning transfer case as your truck wouldn't have a transfer case?

Your pictures above appear to show a 2WD application.
 

Forum statistics

Threads
132,301
Posts
1,865,652
Members
96,888
Latest member
madmoney
Top