Topic: what do I need to do to swap in a g54 transmission?

[shad]

My clutch just went out this weekend and my L52 is making this neat sandy grinding noise so I have a g54 transmission with t-case laying around.
What mods do I need to do to my 82 truck to fit this?
I measured both the L-52 with the t-case to the back flange is 34 1/2" The G54 Transmission is 38 1/2" long measured the same way.
So I have a extra 4" so does this mean I need to stretch my current drive shaft in the front and shorten the rear drive shaft?

I currently have a budbuilt low profile crossmember I heard you can just u-bolt it up to the frame and use the front two bolt holes on the mount.

Can anyone answer any of these questions for me?
Also some pics would be cool too if anyone has any what they used to mount it up.

[shad [OP]]

nobody knows?

[MidgetMike]

I put a g 54 in my 83 and yes you need to shorten the rear d-line and lengthen the front nice thing about the g 54 is the shifters are in the same place as the l 52 and you get better drive line angles. about the t case cross member I made one like the front range which worked out realy well. I would weld in some 3/8" thick angle iron tabs to the inner frame rails and use 9/16" or 5/8" grade 8 bolts if you only use 2 per side. the bud built is a 3 piece crossmember isn't it so you can lift your drive train? weld the frame pieces to yor frame and then bolt the mount to it. Here is my G54

[shad [OP]]

Well I got the L52 transmission out today.
 I took the clutch out and litterly peices and big chunks of the old clutch fell out of the transmission bellhousing.
I also noticed all the fins were bent on the pressure plate. Since I had all this stuff out I did my rear main seal that was seeping.
I resurfaced the flywheel and got the new clutch put in and replaced the input shaft seal on the g54 transmission.
I also swapped over the 4wd switch from the L52 transmission to my G54 they have the same threads.
Now I have to figure out what's up with the budbuilt crossmember since I moved it back it doesn't look right. Anyways gave up tonight I am tired.
I have to see tomorrow if the mount is on backwards or something.

[BigMike]

Looks like you are doing everything correct. You are right about the length, it should be exactly 4" longer. All the spline counts, flywheel dia, clutch, pressure plate, pilot bearing, t/case mounts, speedocable, 4WD indicator light switch, flange diameters and bolt sizes will all be the same, even all 5 forward gears and reverse have the same gear ratios.

The U-Bolt crossmember mount is a good idea that involves almost no fabrication. You might have to slot the four outter most holes (2 on each side) of the crossmember because the frame is wider 4" back from the stock location.

If your truck has a body lift kit, then it will make it much eaiser to get the U-bolts up and around the frame.

And Mike is right, since the G54 uses a forward shift t/case, the shifters will be in nearly the same location as your stock setup.

Make sure you use some GL5 80-90W gear oil when you get it all back together.

Regards,
BigMike

[shad [OP]]

I measured both the front driveshafts

The 79-83 driveshaft's are 19 1/2" compressed and 23 1/2" extended and still has 2" of spline left
and can move upto a 35 deg angle

The 86-95 IFS front driveshaft's are 23 1/2" compressed and 28" extended with 2" of spline left.
They only have about a 22-25 deg angle to them they can be modifyed for more though.

Also dropped off my rear drive shaft to have it shortened.
The guy at the driveline place looked at it and said it's bent and twisted.
Must have been that series of stumps I hit out in the woods last weekend. I wondered why I had a bit of a vibration on the way home.
Anways I told him I want it sleeved with bigger od tubing and balanced.
I'll see how much it runs me to do this.

[shad [OP]]

Well I measured rear flange to the rear diff flange 45" is the length of the driveshaft I need.
I called the shop I dropped off my driveshaft at and gave them the measurement.
So basically they are resleeving the driveshaft with thicker tube and balancing the shaft for $200 and putting new spicer u-joints in it at $26.12ea.
I think it's gonna cost me about $260-270 plus tax.
Do you think that is a fair price for getting a resleeved driveshaft with new u-joints?

[shad [OP]]

Well got the driveshaft back today it set me back $252.22.
I guess it was worth it it's way beefier now and they even painted it gloss black.

[shad [OP]]

Well I put on the driveshaft. It fits but I only have about 1" of compression travel and lots of down travel. I don't think that's right amount of travel.
How much compression travel should I have on the driveshaft 2-3"?

[BigMike]

I think it's gonna cost me about $260-270 plus tax.
Do you think that is a fair price for getting a resleeved driveshaft with new u-joints?

That seems a bit high. Especially considering you can get a High Angle Drive Line (www.highangledriveline.com) for about that price.

Well I put on the driveshaft. It fits but I only have about 1" of compression travel and lots of down travel. I don't think that's right amount of travel.
How much compression travel should I have on the driveshaft 2-3"?

Well, if its the rear shaft, then you dont really need a whole lot of up travel. I would say 2" is ok? I am not sure about 1", but it still might work depending on how soft your suspension is back there.

If it's the front shaft, then you need more like 4" compression, 6"+ extension, again depending on what suspension (spring rates / amount of lift) you are running..

[shad [OP]]

I am running 63" chevy springs in the back with a 8" adjustable shackle set at 6".
The rear suspension is fairly flexy.

[shad [OP]]

I got the transmission mount issue all straightened up and drove it around today.
The only issue I had was the rear output shaft seal started leaking.
I changed it out and it looks like it has stopped for now.
I will still have the driveshaft shortened probably another 1" this week as well.
Also I noticed I seem to have more vibration with the engine it's kinda of weird all the mounts and bellhousing bolts are tight so it's kind of a mystery to me.

I also noticed you do feel a weight distribution difference is is definately noticalbe.

[shad [OP]]

Ugg I am pissed here. I changed the transfer case output shaft seal and it still leaks. There is a groove on the flange where the oil seal sits.
 Do they even make a speedy sleeve for this or am I screwed into having to buying another flange?

[Ramrod]

I paid $90 to get my driveshaft made with the thickest tubing they have. so you might have got hosed

[shad [OP]]

Ya you think? They are like ther only place around here that does that kind of stuff.
 I probably could of paid less but with shipping it would probably work out to the same cost

[shad [OP]]

Well good news I finished modifying the IFS front driveshaft and put new u-joints into it.
I installed it this afternoon it seems like it will work ok.

[shad [OP]]

Some finishing notes and stuff

The reason I used it was

#1 it was free it had 140,000 miles on it and I couldn't justify buying a w56 transmission for it. 
#2 It has way beefier shaft and bearings than the failing L52 transmission I had in it.
#3 It has a removable bellhousing and the same bolt on pattern as a W series so I can still do a Toyota Supra 5MGE or 7MGE engine swap on it.

I measured both the L52 with the t-case to the back flange is 34 1/2" The G54 Transmission is 38 1/2" long measured the same way.

I basically had to get a longer front driveshaft that was 4" longer than the one I had. I used a IFS front drive shaft and modifyed it to be able to move more than 25 deg.
I used this tech to do it http://www.4x4wire.com/toyota/tech/cvmod/

The rear driveshaft had to be shortened by 4".

I was using a Budbuilt crossmember so it can be slid back and reattached using the back of the rear crossmember mounts and using a 2 5/8 - 3" 5/8 square u-bolt.

The transmission hooks right up to the 22r motor no issues same bellhousing pattern as the L52 pattern.
You can use the same clutch slave cylinder as well
I used a new clutch from a 88 to better match it to the 1987 G54 transmission.

Some pics of how the skidplate is and the ifs front shaft and redone rear driveshaft.





Still have to trim the u-bolt excess off and put a washer under the front bolts.

 I think I have to buy a new rear driveshaft flange since this one is grooved and with a new rear seal is still leaking.

Also one note the G54 transmission pretty much bolts right into place.
However I have a 1" body-lift the transmission tunnel still rubs a little on the top of the transmission.
I could probably get away with just hammering the area behind where the shifter sits.
It basically is rubbing where the top plate cover on the t-case is.
If you are running a 2-3" BL you should be fine.