RB25 tranny in R32

[kdwebber]

What driveshaft do you suppose to use??? Will the RB20 one work??

read the thread man he answers that question in detail

[judasentinel]

What driveshaft do you suppose to use??? Will the RB20 one work??

On their own, neither the RB20 nor the RB25 driveshafts would work. You need to use the RB20 driveshaft, CUT the yoke approx 2 inches away form the U joint (the tubing), and then weld an RB25 yoke on to the other end in such a way that the new driveshaft is either equal to the length of the RB20 one OR 1cm longer at the most. You have to do this because the RB25 driveshaft does not have a hanger bearing in the middle that would hold it in place by way of two bolts and its at least 4-5 inches longer. The Rb25 tranny is approx 1 cm shorter than RB20 tranny. Remember that you need a bit of a play in the tailshaft for the yoke to slide in and out (verrrrry little) when the car hits bumps.

And then, the inner diameter of the RB20 yoke is too small to slide ON to the tailshaft of the RB25 tranny. That's why you need to weld an RB25 yoke to the end. Hope that makes it clear, Charles.

[C-unit]

thanks for the really detail explanation. I didnt read it carefully last time. all i saw was.."if u have right driveshaft......." anyways. thanks.

[joecrack]

hey man i ran into a little problem ..
you know the trany mount and the the bracket that bolt up to the body .
well they didnt line up for me i just stuck one on each side ...
but the shifter is in the perfect place (inside the car) ?

did you have to do the same ?

[judasentinel]

hey man i ran into a little problem ..
you know the trany mount and the the bracket that bolt up to the body .
well they didnt line up for me i just stuck one on each side ...
but the shifter is in the perfect place (inside the car) ?

did you have to do the same ?

No, Joe. I had the RB25 tranny mount. And it lined up perfectly. What mount are you using?

[joecrack]

i have both and they both dont line up at the body side ..
and i also had to use the rb20 motor mounts cuz the 25 ones have 2 bolts on the bottom and the 20 one has 1 .

[BigBlueR32]

Hmm I originally thought the tranny mount didn't line up too but if you have the RB25 mount ( does it look any different to the RB20 one you have ) then it should bolt up all 4 perfectly.

Yeah as you stated the RB25 motor mounts are useless.

[judasentinel]

Ray, from what I recall, we used the RB25 tranny mount that came with it, right? Did we remove the center rubber piece from it and put in the one from the RB20 or was a direct bolt-in?

I tried driving it today in the parking lot and there was no grinding in high revs. And then a bit later, it came back......lol. Clutch or master cylinder or syncros........its stumping me. Grrrrrrrrrrr..............

[joecrack]

This is how the rb25 mount line up to the hcr32 chasssis





definatley dont line up .

i even tried using the rb20 and they are the excat same but the rb25 one is beefier

anyone know what the solution is ?

[VortXxe]

Weld on an extension plate, or just fabbing up your own looks like it would be the easiest, it would only take 15 minutes - half an hour to fab up.

[joecrack]

yea i know thats what im doing.
just thought it was bolt up from what people were saying ??
iunno

[judasentinel]

Oh.....Joe, hang on. You remember that the RB20 engine mount is different from the RB25 mount. One has 2 bolts on each side on the bottom and the other has only one, right? Is it possible that you are bolting the engine to one more towards the back than the one towards the front?

If so, can you bolt the engine to the one towards the front? That could bring your motor forward by around exactly the length that you need to get the tranny mount bolted at the right holes? I know its a long shot but I know for a fact that mine matched exactly, and its surprising why yours dont. I will try to take a look at it again tonight and see what exactly we did.

[joecrack]

do yo uhave any pics. . ???im using my rb20 motor mounts man .
there is only 1 way to put them on .
the 25 ones dont fit .

[joecrack]

ok well i just got my drive shaft back from the shop ./
and they just ended up removing the the yoke at the u-joint and pressing on the rb25 yoke on .
no cutting welding balancing required .






hope this helps some people out.

[klys]

Stickied

thanks for the write up