Differential issue - extreme huge trouble

[MartinS]

Hi folks!

Last year in november i decided to rebuild my rearaxle assembly to the fullst. I bought a new Cusco RS 2way differential and a Weirperformance 4.7 Kit. All the small parts included It was around 2000€+. Wheel bearings, brakelines, new calipers, new discs, gasket kit, etc. Really I like to do thinks clean and nice!



We bolted the axle to my car around end of february, with a new Pass Racing one piece drive shaft. Very soon some isues started. After the first 500km the shit became in credibly loud. And the differential was leaking through the pinion seal.

I decided to take it to my mechanic who did the alignement on the differential. He is experienced and working for Toyota since more than 20years. He's a true hachiroku mechanic.

We analysized the problem an thought that the pinion seal was leaking, because of the driveshaft which was too long, as we thougt. (My car is pretty low with the current setup maybe 70mm+). We replaced the driveshaft with the original one, did a pumpkin rebuild with a new gasket and a new set of pinion bearings. Then I drove home and went to my first trackday this season. The car was louder, but did a good job. Until i arrived at home, the play in the rearend became noticibly bigger.

I left the car in the garage and didn't take it out for a ride for about 2 - 3 weeks and then i decided to redo the whole story. I put the car on jacks in my garage and took down the differential assembly. I thought this time I'm going the safe route. I took the differential to a place 150km away from my house to a real hachiroku maniak. (They built some really fast AE86 hillclimb cars and engines with 220hp+). I really new the guy was doing a grate job and his reputation was more then worth a shot.

Friday I finaly got the differential back home. I had a chat with him and he said the pinion and crown has some marks of missalignment, he did a few tweaks there and here and it should be good. Maybe it's a bit noisier then a std. but till winter it will be more than good and no problems driving it on daily basis. I was really confident, that this time the shit will come to an end. I put so much energy and passion in this rearend, that it had to come to an end.

Saturday we went playing poker with a friend of mine and came back at 0230. We decided that we bolt the diff to the car as i couldn't sleep. 0500 I was finally in bed. I couldn't do a testdrive at night, as i was still a bit tipsy from the poker session.

Today I got up in the morning turned over the car and did maybe 300m. It's a +"*ç%&/()ç*%*"*ç&"&%R/& bullshit isue. The noise is still here and nobody knows why. I'm really finished I don't see any other solution then selling my car or to push it into a river!

If somebody has an idea, hint, feel free to post it here.

Cheers

[XJS]

I'm in the same shoes.

Bought the car with a dead diff, so rebuilt it, mated with a fresh axle incl. new bearings. Noisy. OK, next round nr2, changed every bearing (side, fron gear, back gear) and seal in the diff itself. Still extremly noisy. Round nr3, changed the gears and put back into the old axle. Still noisy, but it's usable...
Just for the record, the first set of gears was 330000lm used standard LSD 4.3, the second set was a 260000km opendiff 4.3.

My last hope to change the gears to a brand new Toyota item again, with new spacer.

[Jimmi The Kid]

Have you done the break-in procedure for the new LSD?
My KaaZ LSD also make some heavy noise, specially when driving out of roundabounds. I did do the break-in, but this was not enough. But after about 1500km it stopped.
Also remember to change the diff oil after 1000km and then every 5000km. And use ONLY LSD aproved oil.

The driveshafts can make some scraping noise, if they are bended. You can hear it if you slowly push the car. Unfortunately I have tryed that. It cost me a new axle.

[MartinS]

Yes all done.

It is the finaldrive alignement for 100% sure!

[robokill]

relax Martin, I have seen axles make noise, whine and sing. Never give up on them. If the final drive isn't to tightly set its a matter of driving. Worst case that can happen is that you blow it up. Meaning you probably waste a diff and a crown and pinion.

You said you bought the Cusco RS. As far as I know from Cusco there are 2 types. One racing and one street. Which one do you have?

If its the racing I think that it will always be louder. Don't sell the car because one thing isn't perfect. Thats the Hachiroku.

[Ivan141]

Diffs dont make whining noises... gearsets do. If yours is worn due to improper adjustment / lubrication there is not much you can do to get it quiet AFAIK.
I did read somewhere that you need to concentrate on getting the 'coast' side contact patch where you want it on used gearsets, but I dont know how much that will help in your case.

[jondee86]

Kind of unusual for a pinion seal to leak so soon. Did you use a solid
spacer or a crush tube when setting up the pinion ??

Did it feel like the pinion flange had any sideways slop when you pulled
the diff out ?? Did you check that you had end clearance on the one-piece
shaft by sliding it forward after you unbolted the flange at the diff ??

What kind of noise are you hearing ?? Rattling... grinding... whining...
banging... cracking... chattering ?? Does it get worse under any particular
driving condition... rpm range, load, acceleration, cruise, cornering ??

As said above, gears can take a while to bed in properly, but normally
you could expect the noise to decrease once the components have gone
thru the bedding-in process.

Cheers... jondee86

[MartinS]

I gears had time to bed in. I was driving more than a 1000km's in total.

The noise is coming from the CWP assembly. It is a whining, grinding noise. And just for your imagination. At 70km/h i can't hear the radio on level 40. Usualy i'm listening to musik on level 18 - 20 when i cruise around town!

Next things i'll try:
- New toyota 4.8
- New TRD solid pinion sleeve
- New pinion bearings
- New casing (maybe something is wrong with the housing)

I've spoken to ronny over at c4ag and he had also pretty strong isues with the finaldrive assembly. The noise went away by changing the housing. As far as I remember, we had also issues mounting the 2 brackets for the differential bearing, it didn't fit perfeclt.

[ZaX]

Martin, don't give up.
My white AE86 made lot's of noises in the diff but never failed.
New casing might be solution for your problems.

Keep up!

[irishtwincam]

My newly built differential arrived


I have a used TRD LSD whch has been broken in already.
The CWP, bearings etc are all new.

This is what I researched and was told by my diff builder.

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New CWP break in procedure:

I recommend covering the ring gear teeth in the Redline Friction Modifier/Break-in Additive, and turning the pinion several times (so then it too is coated) prior to re-fitting the diff unit to the axle.

Then I recommend using a superior synthetic gear oil such as the Redline 75W90 for break-in to best cope with the extra heat of break-in.

After driving very lightly and slowly for the first 10-15 miles, you must let the differential cool for at least 2 hours before proceeding.

Drive very easy, light and slow (30-40 mph is OK) for 500 miles before loading the differential (ie no faster driving/drifting). Normal gentle urban driving is ideal.


Change the gear oil after the first 500 miles! This will remove any metal particles or phosphorus coating that has come from the new gear set.
It would be even better to change the gear oil after 100 miles or so, then again at 500 miles.

After this, progressively faster speeds may be driven for short distances (less than 15 miles), but let the differential cool before continuing during the first 50-100 miles of higher loads or faster speeds.


ANY OVERLOADING OR OVERHEATING CAN CAUSE THE GEAR OIL TO BREAKDOWN AND THE RING & PINION WILL WEAKEN.

So 15miles uber slow
100 miles <30mph (change oil)
400 more miles <30 (change oil)
50mph for 15minute intervals, then cool diff for 2 hrs (100 miles)
Change oil.

~600mile break in.

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This is the break in for a new LSD core.
http://www.drifting.com/forums/tech-disc...u-s-a.html




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Did you do any break in?