engine and drivetrain 245/11 Close ratio tranny in- but its got a whine...

[peteinjp]

I picked up a 245/11 a few years back and had a reputable vendor take it apart, check it out and switch the housing with a 245/5 case. Supposedly it was good to go in terms of the bearings etc. Now that I finally got it in there is a slight but clearly audible whine that follows the engine RPM. I can hear it in first and second but by the time I get to 3rd the sound of the tires (pretty loud tires) get in the way- so I think its there in all gears but I'm not totally sure. My buddy who is totally un-mechanical also heard it right away.

The sound is just like a set of straight cut gears- but barely audible relatively. The only other item that I changed at the time it I put in an aluminum flywheel from JB racing.

As a way of stciking my head in the sand I'm hoping that the allen head bolts in the JB racing kit are making that pretty little sound...... but unless there is something different about the close ratio units I fear there is a tranny rebuild in my future...... Which I will have to do myself as shipping it back from Japan is just too expensive.

So what ye all figure in terms of the culprit??

Pete

[Kpeters]

If it's the tranny you probably still got some good life ahead of it. That is if it is actually barely audible. I've seen transmissions on daily drivers really whine for an indeterminate period of time. Basically it could just go on and on as long as are not too hard on it.

Maybe it's not the most perfectionist way but I would just leave it alone and spend my cash in more fun stuff but hey that's just from what I've experienced myself.

My E21's diff for example has been whining a bit for 10 years and now it's got a 2.7 engine on it. It hasn't gotten worse and I doesn't bother me for the time being.

That being said if it starts really whining I would stop using it to avoid further damage.

[Hans]

As I understand it, the early C/R boxes need a specific fluid because of the synchros. Perhaps this is your problem.

[allbim]

Probably the input or counter shaft bearings. The transmission in my daily driver (E36) has been whining for the past 126000 miles, but has not gotten any worse.

[Mike Self]

in the tranny? Red Line MTL seems to be kinda magic on 2002 gearboxes--it sure made my 73's 4sp with B-W synchros shift as smoothly as the Porsche syncyro gears in my '69...something it had never done before.

A little whining isn't too out-of-the ordinary for an older gearbox, even with new bearings...

Oil change is worth a try...

mike

[c.d.iesel]

try the original bmw spec oil: SAE75/80 GL4 Gear oil -

Not Hypoid gear oil or GL5 - if it is the gearbox

causing the noise - do not use synthetic

oil for noise reasons

other source for the whine can be:

are you using solid/urethane mounts at the trans,

rear diff, mounts, and rear subframe mounts ?

if yes then it's the rear diff that's howling through

the body from lack of original rubber mounting

insulation

is the body stripped of insulation? no back seat?

same as above - lack of body sound deadening

and or in combination with all the urethane mounts

is source for the read diff singing through the

body shell- normal

[tim385]

Just out of interest have you tried coasting at speed with the tranny in neutral? With the clutch in and with the clutch out , as CD said could be diff noise, coming thru.Worth a try just to isolate a few things.

[allbim]

How can it be a diff noise if it follows engine RPM?

[peteinjp]

Thanks for the thoughts guys. I have redline MTL in it. The previous 5 speed did not make this noise. My thoughts were exactly this- use it and see if it gets worse- however I don't exactly baby it......

I suppose my concern is say- 10 years down the road it needs a rebuild- will I be able to get the bearings etc or will it be an waiting game for them to show up from someones stash. IF it gets worse during the course of the year then I think I will go ahead and order a set.

I do recall that the original mileage was 70,000 and the guy I bought it from said he drive the car with the transmission in it and it was working just fine. So I'm inclined to think that - well I'm thinking too much.....

Pete

[c.d.iesel]

..... well then ~

with the car on 4-jack stands - you underneath

with a stethescope and a helper in the drivers

seat working the throttle and holding rpm/mph

at the peak noise level

- you touch around the trans case to pinpoint

the noise location.

listen to the center bearing and diff also

- you'll locate it

Easy

[peteinjp]

That'll do - assuming it makes the noise without load.

Pete