NEED 901 TRANSAXLE ADVICE, howling noise on acceleration Options

[9146FAN]

Orig 914/6 transaxle was howling on acceleration. It was most noticable on light acceleration and around 2500-3000RPM. Oil level was full.

I removed the trans during the resto, and I'm converting to side-shift. Looking inside, I don't see any noticeable Ring & Pinion wear, but I could be overlooking something. Carrier Bearings look slightly dull in the race, but not pitted.

I don't see any adjustment for the Ring & Pinion except for the shim under the 1st Gear Set. I also noticed that there were 3 paper gaskets between the Intermediate Plate and the Main Housing; does anyone know if that could cause a Howling Noise?

My questions are:
1. Does howling on acceleration mean Ring & Pinion noise?
2. Can the Ring & Pinion be adjusted?
3. Why would someone use 3 paper gaskets?
4. What would noisy Ring & Pinion wear look like?

Any advise will be apreciated.

Eddie

[Aaron Cox]

shims between diff and carrier bearings set ring gear left and right,

gaskets under int plate set pinion depth

[ClayPerrine]

The paper gaskets between the intermediate plate and the housing are there to set the fine pinion depth adjustment. If they are not correctly reinstalled, the pinion depth will be off.


The howling could be the ring and pinion. I suggest that you take it to a specialist and have it checked.


Are you in Norcal or Socal. If you are in Norcal, I suggest Cap'n Crusty.

[9146FAN]

Guys,
Thanks for the info. Do you know what the procedure is for checking backlash on R & P?

I'm in SoCal.

[drewvw]

My ghia has had a howling in the transaxle for about 10 years now. You can really hear it when the top is up. Its not supposed to be good, but my tranny has never died on me.

Then again, it hasn't had 1st gear for about 10 years either..... (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

[Aaron Cox]

where is roosmore?

thomas (one914racer) and joe sharp taught me how to rebuild mine.......

AA

[9146FAN]

Drew,
Nice Ghia info. Your car sounds like a Spitfire I used to own in the mid '70's (non syncro 1st gear).

Aaron,
Rossmoor is between Seal Beach & Los Alamitos in OC

[bondo]

If it does it in every gear, it's most likely your ring and pinion. Did you check all the bearings? (the ones in the intermediate plate are hard to get to but worth checking) Bad bearings can cause the ring and pinion to not mesh right and make noise (and bad wear).

The pinion depth is coarse set by shims at the end of the gear stack, on the pinion end. It is fine tuned by the gaskets, which are three different thicknesses. You can use any one, two, or 3 of the gaskets to get the fine tuning you need. I don't think I've ever seen all three used, and I'm guessing it's somewhat rare. It's quite possible that someone decided to re-seal the trans and just used everything that came in the kit, which could explain the noise.

The carrier bearing preload is set by the shims under the carrier bearings. The distribution of the total shim amount between left and right sets the backlash.

It's all very complicated, and requires special tools to measure. Unless you're a masochist or really cheap (I'm both), I suggest you have someone look it over and make sure you've at least got servicable parts. If not, it's not that hard to transfer the /6 gears into a regular sideshift. As long as you keep everything from the sideshift except the gears you take from the /6 trans, you won't have to reset pinion depth. (make sure you measure the gaskets of the donor trans!) It would probably be wise to measure the gears on the pinion shaft of the sideshift, and the gears on the pinion shaft of the /6, and make sure they're the same.. any difference could be accomodated with gasket adjustments. (first gear doesn't apply because it's on the other side of the intermediate plate and wouldn't affect pinion depth.

The factory manual covers all this stuff, but it's hard to follow and can really make your head hurt.

[brp914]

1. I've never had r&p problems in 250k mi. had everything else. the time I had noise on accel, it was intermediate plate bearings. If accel is noisier in low gears rather than high, that would further confirmation.

2. the r&p can be adjusted, but requires special tools.

3. see prior responses

4. r&p wear should be rather obvious on inspection, but I wonder if you are jumping to conclusions. I took a class in transmissions and was told that r&p noise would not be confined to accel. It would be present under load in drive at constant speed, or decel.

[dekman]

Mine developed a howl.....ended up being a worn out ZF differential. Do you have a diff? Now with new lock up plates(set a 80%), the howl is gone. My 2 cents. (I'm a certified NON-expert.) (IMG:http://www.914world.com/bbs2/html/emoticons/wavey.gif)

[Twystd1]

I totally don't know shit...

BUT:...................... (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

I got taught this last week. Based on the man I got this from. This is PROBABLY relaible info.

HE SAID:

You can't tell what the wear patterns are on some R&Ps by simply looking at it. And here is why.

Let me give ya a for instance. Sometime in the past someone has rebuilt the tranny. This someone doesn't get the R&P set exactly right.

The tranny gets installed and eventually starts making noise.

Might be 100 miles or 5K miles after the rebuild. Might even be longer.
Cause ya just never know.

The problem herein is that the R&P has now taken on a new wear pattern. And you can't see it.
Not even with prussian blue. Because it doesn't show the original (correct) pattern anymore
It only shows the new wear pattern. Which is wrong.
And it only has to be slightly off to make noise.

Therefore... to the naked eye. It looks correct. But it ain't.

So what does a man do in this circumstance.

Easy.

Take it to a pro with the right tools. And a REAL working knowledge of these specific R&Ps.

That said.......

Does this make sense to you guys? Does to me.

Clayton

[redshift]

QUOTE (ClayPerrine @ Apr 9 2006, 10:45 PM)

If you are in Norcal, I suggest Cap'n Crusty.

Yes, especially if your senses haven't been wrapped upon lately.

Just tell him you know it all!



M