Can you put a 6L90E into a 4L80E '98 K2500 Suburban 6.5TD?

[THEFERMANATOR]

Was yours the earlier model overdrive or the updated one? I know they changed design sometime in the last few years

I'm pretty sure mine was the late model as it wasn't the same LAYCOCK unit as my uncles in his F-350 he put in back in 93.

 

[GM Guy]

You making me think about putting the 3:21 since my rig is a 2wd. My truck sucks fuel at highway speeds. I need to drop the RPM like you mentioned. I still have 2 years in college which is about 15 hwy miles one way. And we all know fuel prices have no where to go but up.

If I was you I would find a second axle to do that to so its roll in, roll out, unless you want to make one of your trucks the tow beast, and mod the other for fuel economy.

 

[Michaeljp86]

If I was you I would find a second axle to do that to so its roll in, roll out, unless you want to make one of your trucks the tow beast, and mod the other for fuel economy.

Ive been doing some thinking on that. Since my truck is my tow machine I should probably consider that in any gear changes.

I think Im going to sell one this summer. Michigan is making the plates $100 a year min. If you have a newer car where your paying over $100 its going up 80%. With the cost of ins and everything else I think Ill have to sell it. Sure is nice when you have a problem. You can just swap parts to find the problem.

 

[Ed HD]

I would say probably a second cross-member would have maybe solved your problem, Ferm? Just my guess. Sounds like the OP is in a lose-lose situation here, lol.

 

[THEFERMANATOR]

I would say probably a second cross-member would have maybe solved your problem, Ferm? Just my guess. Sounds like the OP is in a lose-lose situation here, lol.

I tried a temporary cross memeber and it made no change, that was when I gave up on it.

 

[Husker6.5]

I tried a temporary cross memeber and it made no change, that was when I gave up on it.

Hmm, makes one wonder if perhaps it was an internal imbalance in the GV OD unit causing the vibration? There are way too many GV units out on the road right now, including one I know in a 6.5 in Massachusetts, that have given lots of trouble-free miles of service.

 

[Michaeljp86]

Just out of curiosity talking about gear ratios, does anyone know how the GM transmission compare to other pickups? Fords, dodges?

 

[THEFERMANATOR]

Hmm, makes one wonder if perhaps it was an internal imbalance in the GV OD unit causing the vibration? There are way too many GV units out on the road right now, including one I know in a 6.5 in Massachusetts, that have given lots of trouble-free miles of service.

I could see 1, but 3 in a row all had the same vibration.
GEAR VENDORS worked with me right up until I had had enough and wanted them to honor there money back guarantee.

 

[tanman_2006]

I've got enough trucks to dedicate a tow rig and dd/econ rig. If I were to need to downsize and run 1-2 rigs I would first ad att then try 4.10's w/ gear vendor/ranger splitter or stand alone 6 speed Allison.

Sent from: Source Unknown

 

[tanman_2006]

Just out of curiosity talking about gear ratios, does anyone know how the GM transmission compare to other pickups? Fords, dodges?

Similar, AFAIK they are all .7-.75

Sent from: Source Unknown

 

[Husker6.5]

I could see 1, but 3 in a row all had the same vibration.
GEAR VENDORS worked with me right up until I had had enough and wanted them to honor there money back guarantee.

I didn't realize that you went through three of them, wow!