Help..

[nissan200sx.dk]

Hi.

Just got my car out running again after a engine block change. Its a RB25DET.

OLD block was a R33 GTS frontcut. RWD from the start. Had no problems here...

New block is also RB25DET but it had 4WD oil pan mounted, and automatic tranny. No idea what car its from. Mounted my RWD oil pan, had to modify oil pickup to make it fit. Bought it as a spare engine, just to get the block...

But now my car has BAD vibration / noise comming from transmission. Im doing 80km/t, 5th gear, clutch in, and then rev up to ~3000 then there is a bad bad bad vibration / noise comming from tranny. Not noise like a misshift were teath are grinding. BRRRRRRR noise. If im going slower its takes a little less rpms to get the noise / vibration.

I first found out when just driving aorund slowly, it sometimes does the same vibration / noise when shifting gears. Depends on what speed , gear, etc etc..

This problem has only been here AFTER i changed block.... What could the problem be with using a RB25DET RWD 5 speed tranny, on a RB25DET 4WD block, automatic? I know bottom mounts to support tranny isnt there as std, but have made my own.

I am thinking a little over if it could be the "pilot bush" in crank, or maybe something with my clutch? Does the RB25DET 4WD automatic has the pilot bush installed as std?? or is it missing as std.?

Im a little pressed for time, as i need to sort this before the end of the weekend, as school exsam starts monday...

Edited April 19, 2008 by nissan200sx.dk

[Duncan]

OK I've probably got bad news for you.

If you have a 4wd rb25det it was probably out of a stagea. and most stageas are auto. and auto crank does not have a spigot bush or pilot bush as you call it. It is the same crank so you just need to put the spigot bush in.

They are about $10 from nissan, and they will probably in be stock because they are same as rb30.

WIthout the spigot bush the end of the input shaft from the gearbox is not supported properly and is probably moving around. I wouldn't drive it any further you are probably doing damage to the gearbox