My transmission is growling at me

While driving my IM home on Saturday night I noticed a growling sound coming from the transmission, when I took my foot off the accelerator.
I have a heavy duty clutch and lightened flywheel. Would either of these two items, separate or together, cause this growling sound? Maybe growling isn't quite the word I'm looking for....how about a bunch of ball bearings rolling around in a metal bucket?

My tranny makes a similar noise on deceleration, Ron. I only hear it with the top up. It got worse when I put the Berg 5 in it. The primary reason for mine is the tight fit of the over-sized nose cone.

Check your fan for leaves, and the gearbox for fluid.
I like to put the torsion on jackstands, so the axle tubes droop, then add fluid until it dribbles out the filler a bit.
If she's wet, she's happy. That's what I always say.

What's take on using synthetic trans fluid? Does it work with old gear boxes? My Yota 4Runner started to jump out of 3rd gear - changed fluid to Valvoline 70W90 synthentic and never jumped out again plus it seemed easier to shift especially in cold weather.

Ron wrote: "I have a heavy duty clutch and lightened flywheel. Would either of these two items, separate or together, cause this growling sound? "

Highly unlikely. Does it happen in every gear, or is it more pronounced in one gear over others (like third)? Louder on acceleration? Deceleration? Both? If you get up to highway speed (say, 50mph), take it out of gear and go to idle, what happens to the noise? Is it engine speed related or external speed related? Is it clutch related? i.e.; goes away when the clutch is depressed?

First thing I thought of was whether Henry put a Urethane front transmission mount in. I don't know if he uses them with bigger engines, so thought I would mention it. Those tend to amplify any mechanical noise from the transmission through the frame like a megaphone.

The next thing I would suspect is either of the bearings just inside of the nose cone (one input and one output shaft). The good news is that they can be replaced without pulling the transmission case apart. The bad news is that you'll have to pull the engine and transmission to get at them, but it's an afternoon job.

When I've seen that growling, I've never made it better by switching to synthetic lubes (although I did make it worse, once!) but, what the heck....you could try it. I've had mixed luck with synthetics in early VW trannys. Some peope love it, some hate it, no one's in between it seems.

Oh...one last thing: When in neutral with the engine running, listen for any noise then step on the clutch pedal and listen for any change. It may just be a dry or growling throw-out bearing (and it would be engine speed related). It should change markedly just at the transition of no-load to slight load on the pressure plate.

Hope this helps. You getting the same rain as Washington state?

gn

Yes, we're getting the same rain as Washington State-probably more! If it doesn't stop soon I'm going down to my local lumber store and buying a shit load of lumber. :-)
The noise only occurs on abrupt de-acceleration, and it's only noticeable at highway speeds. Mind you, I haven't driven the car since I brought it home last Saturday....damn rain!

I put synthetic fluid in my tranny while I had everything out of the car. I'll have to see if the noise gets worse. If it does I'll pull the engine and tranny.

Ron,

The synthetic fluid might be the problem. It might be 90wt but synthetic is usually thinner but has the lubracation of the thicker oil. A slightly worn ring and pinion with a little extra gear lash will give noise on deceleration with a thinner oil. Unless it gets worse which means a bearing roller might be going bad I would run it for now.

Glad you at least getting a little seat time on that fine looking ride.

Even your transmission is bent outta shape by the lack of cold start on the EFI... (gggrrrrr....dang no cold start....grrrrr)

angela

Ron, I've been meaning to go out to the garage and check for sure, but I remember my gear oil being specifically for yellow-metal synchronizers.
As far as that goes, I think GL-5 is the one that's NOT safe for our cars. I believe GL-4 is; I think that's what's on the shelf in my garage. Somebody will have to back me up on that, since I'm not at home right now.
I have heard of people using regular 80w-90 motor oil, but do not personally know anyone who's done that.

I've done some searching on Samba, and there seems to be divided opinions on the use of GL-5 in our transmissions.
I'm considering draining the synthetic fluid and replacing it with Swepco, to see if that decreases the noise.

Stick with the GL-4, preferably one that says yellow metal safe on the bottle. GL-5 has more sulfur compounds which is what attacks the syncros.

Ron what transaxle are you running.

Peter, I'm not sure what you mean. The only thing I know for sure is it's an IRS. When originally I sold the car five years ago I threw away all of my paperwork.

Ron,
If it's any consolation I had a "growling" on decel from my trans too when I put in the CB engine and a new trans. I'd never heard before whan I was running the stock set up. I can't remember who told me it wasn't uncommon but I just got used to it. The trans ran strong for as long as I had it.

Ron, I changed to the Valvoline 75-90 synthetic a couple years ago. No real need to but it did make it shift MUCH easier when cold. No problems in 2-3 years. You are supposed to dump the oil and switch it out after 500 miles on a new or rebuilt VW unit, as per Bentley.

Ron, I was wondering if it's a 4 speed VW or maybe a 5 speed Porsche.

Peter, it's a VW 4 speed box.
Daniel, the tranny had been sitting around for a couple of years, so I drained the old fluid and put in Red line before putting the tranny back in the car.
Peter, I'm going to drive it and see if the noise gets worse. If it doesn't I'll just learn to ignore it.

Good luck ignoring it. I have a similar noise that I begin noticing about 3 months ago. It