Installing AWD trans in FWD?

[1glaserfwd]

Well my stock fwd trans died with my hx40 at only 18psi. I have a spare 92 awd trans that I am planning on using. I have researched that its much stronger. I know I need the flywheel, starter plate and axles for an awd, as well as the shifter arm from my 90, plus have the diff welded. My question is since its gonna be in a fwd what do I do with the VC? How do I go about plugging the tranfer case hole? Please only post if you know. I dont wanna bunch "just get another fwd trans". Thanks in advance.

 

[dsmgst1996]

Not trying to give you a bunch of what you dont want ... but you could sell that awd for the price of 2 fwd the benifit will really not be worth the work it takes to do that i would just leave the tf shaft there if you are dead set on using that tranny

 

[ed1380]

Install a viscous locker and just keep the transfer case shaft.

 

[1glaserfwd]

Reason I am not just putting another fwd trans in cause its gonna break again in no time. I did a lot of research and in fwd trim the awd trans can actually be a cheap alternative to builing a fwd one. Hoping thats the case. I was not aware I could leave the shaft in. Thanks for the input so far.

 

[98gst14b]

I cant really see how an awd trans is stronger, I have litterally had both transmissions apart next to each other and they are really close as far as gear thinkness/dimensions. Most of the parts that break i.e. hub sleeves and syncros are actually the same part number between the two transmissions, so I would have to agree with dsmgst1996 on this, but if you are hard for it then lock your center diff, pull the xfer shaft and have an aluminum plug machined in place of the output shatf seal.

 

[cianfar]

You can take it to a machine shop and ask them to make a plug that will ensure no leaks from the transfer case shaft. The cost will depend on how much the machined shop will charge you.

 

[Blindsey]

Anyone else with experience? We're about to tear into the AWD.

 

[twicks69]

You can take it to a machine shop and ask them to make a plug that will ensure no leaks from the transfer case shaft. The cost will depend on how much the machined shop will charge you.

Just use a 45mm freeze plug and epoxy it in. Weld lower pinion gear in center diff housing, remove upper pinion gear, spider gears and cross shaft, remove viscous coupler, detent ball, snapring and output shaft.

Just be sure to use whatever front differential matches your axle splines.

Some of the AWD transmission gears and shafts available are stronger and there are more gear ratio options and 4 final drive options. The AWD transmission case is also stronger than the fwd.

Simply put, you can get a stronger 1/2 shift fork and 1/2, 3/4 shift rail assembly for use in the AWD trans while there are not some of these other options available at all for the fwd box.

 

[1qkfwd]

You beat me to it Tim

Ive always ran an awd trans in my fwd. Just like Tim said Plug the hole and ditch the VC. No need for that added weight. The awd case holds the gears together better. Plus the ratio is so much better. If you wanted to you could just use the 2G fwd trans and bigger axles if you wanted to stay fwd. It drops right in.

I will have a solid comparison between the ratios of the fwd and the awd trans here in a month or so. Ive been running the fwd trans with my 14B car just to see what I can get out of it. Ill be doing no other changes besides the awd trans swap. If it goes how I think its going to go, the awd trans will ET better with a slight loss of mph.

Dont forget youll have to run a bigger tire with the awd trans.

 

[1glaserfwd]

Just use a 45mm freeze plug and epoxy it in. Weld lower pinion gear in center diff housing, remove upper pinion gear, spider gears and cross shaft, remove viscous coupler, detent ball, snapring and output shaft.

Just be sure to use whatever front differential matches your axle splines.

Some of the AWD transmission gears and shafts available are stronger and there are more gear ratio options and 4 final drive options. The AWD transmission case is also stronger than the fwd.

Simply put, you can get a stronger 1/2 shift fork and 1/2, 3/4 shift rail assembly for use in the AWD trans while there are not some of these other options available at all for the fwd box.

Thanks for the replys guys, I talked with jacks and there telling me to leave the VCU in. They told me to send that with the center diff for welding. So many different opinions I dont know what to do . I guess I can just use awd axles with this trans. Is the Vcu supposed to be welded to or am I just confused? After re reading it maybe just for helping them weld. Here is what they emailed me back.

"Yes, leave the VCU on it as that will allow me to keep it in alignment for easy install on your end later."

Also to clear up any confusion the awd is indeed stronger, here is another email they send me

"the AWD trans is far stronger than the FWD. In any high torque application involving the FWD, we always recommend AWD "

You beat me to it Tim

Ive always ran an awd trans in my fwd. Just like Tim said Plug the hole and ditch the VC. No need for that added weight. The awd case holds the gears together better. Plus the ratio is so much better. If you wanted to you could just use the 2G fwd trans and bigger axles if you wanted to stay fwd. It drops right in.

I will have a solid comparison between the ratios of the fwd and the awd trans here in a month or so. Ive been running the fwd trans with my 14B car just to see what I can get out of it. Ill be doing no other changes besides the awd trans swap. If it goes how I think its going to go, the awd trans will ET better with a slight loss of mph.

Dont forget youll have to run a bigger tire with the awd trans.

Wow had no idea a 2g fwd trans would go on a 1g. Thanks for the knowledgable info. I already have this awd so I wanna do this. Do you think my 24.5" slicks are gonna work? Car is gonna be on 35psi hx40 2.3. Hoping for low 11s or high 10 second slip this season!

 

[GRNDSM]

I think that you are focusing on the wrong upgrade! Stock for stock, there isn't much difference between the strength and AWD first gear is useless on FWD (unless you get tall slicks). I would worry more about putting a better shifting tranny, because it doesn't get much worse than 90 trannies . And if you are getting 91+ trannies, you will have to get matching shifter cables and shifter.

If I had to use AWD tranny in FWD, I would get a welded center diff and try to remove all the RWD related parts (VC and the Tcase shaft), why carry the extra weight? But relying on VCE as the means of locking your center diff on higher torque cars (above 400-500lbs*ft), is not a safe solution!