LS1x2

iTrader: (11)

I've got a t56 now. I went round and round with the hydraulic setup to get to where I could band shifts at WOT. Now that is sorted out with a mceold m/c bled properly. The thing is the tranny still feels "notchy". It's not smooth. Seems like I am having to wait to long on the synchros to spin up.

I'm wodering if this has something to do with the fluid. I'm using Redline Synthetic just like I did for years in a lt1 t56 I had. I have heard of one person saying synthetic fluid caused a problem in there ls1 t56. Anybody know anything about this?

smokin' joe 00 ss

I used Dino oil in mine Valvoline, make sure you have the adjustable rod adjusted right on the m/c it should just slip over the stud on the clutch pedal without pushing the clutch pedal in anymore than that would preload the clutch and cause notchy feeling.

LS1x2

iTrader: (11)

Well I switched to some Aamco Dexron 3 fluid. It is much better. I'll try moving the m/c up a bit just for the hell of it. It's not preloaded though b/c the rod is not pushed in b4 the clutch is pressed. Right now the clutch pedal is just barely lower than the brake pedal. Where is it stock? I don't have the spring on the clutch pedal.

ROLSCH

SEVERAL YEARS AGO I HAD A CHANCE TO TALK TO THE CHIEF ENGINEER AT BORG WARNER (THEY DID THE ORIGINAL DESIGN AND MANUFACTURING)HE SAID THAT B-W USED ATF IN ALL TRANSMISSIONS TO AVOID CONFUSION BETWEEN MANUAL AND AUTOMATIC LUBES.THE INTERNALS WERE DESIGNED TO WORK PROPERLY ON DEXRON. HE TOLD ME THAT IT WOULD BE OF MINIMAL VALUE TO USE SYNTHETIC.WHEN I SAID I WAS GOING TO CHANGE IT ANYWAY HE RECOMMENDED MOBIL 1. I SWITCHED TO MOBIL 1 ON MY '95 Z-28 AND LATER ON MY '00 WS-6. IN BOTH CASES THERE WAS A SLIGHT IMPROVEMENT. FOR WHAT ITS WORTH.

trackbird

iTrader: (4)

I'm running Mobile 1 and it did seem to remove some to the notchiness from my gearbox. I changed fluid at 16,000 miles....

Inspector12

iTrader: (29)

Mobil 1 ATF right not the gear lube like in old style 4 speeds.

LS1x2

iTrader: (11)

I'll keep that in mind. Between the redline synthetic and the Ammco dexron three it is night and day difference! No way in hell I would use the redline again.

trackbird

iTrader: (4)

Mobile 1 ATF, that's correct (guess I should have said.

The Redline is great stuff, I'm suprised that you ahd problems with it. I did once see an article (on the ZF gearboxes from the older vettes) that mantioned that synchronizer "dust" would build up on the synchros (during gear lube testing) at about 12000 to 18000 miles due to centrifugal force "spinning" it against the synchro walls and casuing a buildup. They then suggested a 16,000 mile fluid change interval. It may not be the oils fault....you may have seen something similar. Just a thought....

LS1x2

iTrader: (11)

This was a fresh A3 to m6 swap. The fluid had 800 miles of use. Swapped the fluid and ONLY the fluid. Car shifts probably 3 times smoother now.

2001CamaroGuy

iTrader: (6)

I use Redline without any problems (37,000 miles on it). I didn't know about that syncro dust thing. I may change the oil just for good measure next time I do an engine oil change.

trackbird

iTrader: (4)

http://www.zfdoc.com/faq.htm

Here is the article that mentions the oil testing. Not quite 1/2 way down the page...it is one of the answers....

EdmontonSS

In on of my t-5's I bought used for my '83 Firebird, i changed fluid to Redline ATF, the syncros would grind and was very notchy. I added GM friction modifyer (for anti-slip differentials) and it smooothed out, I think the redline is too slippery for the syncros to work correctly. Auto's have clutch bands and ATF is probably designed to allow some friction between bands. Not an expert opinion but just my experience...

trackbird

iTrader: (4)

The GM friction modifier is to make lube "more slippery", it is a conditioner to keep clutch chatter to a minimum on clutch or cone type posi units....But it may have thickened stuff up a bit???

Zeta

I have wondered and asked what the friction modifier does. The only real response I got was it increased the friction between moving parts. One data point out of many misses.

Bottom line is there is stuff that is magnetic and non-magnetic that wears in the transmission. I have yet to hear a good argument that metal particles suspended in fluid makes a good tranny lubricant.

Examine the fluid the next time you drain the hot tranny fluid.

EdmontonSS

The way I understand "friction modifyer" is to increase friction when the fluid is under pressure as in a cluth-style posi or syncro-mesh without friction modifyer, the fluid is TOO slippery. I believe there's probably small particles of graphite or somthing, so that in close tolerances (less than .002" or bearing clearance) the "friction surfaces" can grip. These particles wouldn't affect the normal bearings with clearances of .002" and up of course....

trackbird

iTrader: (4)

A clutch type (or cone type) posi can (and often will) make noise if it is used without the friction modifier. The noise is from the clutches grabbing and slipping, Auburn says this will not hurt the dif, but it is irritating. The modifier is designed to help these parts slide without grabbing.

http://www.auburngear.com/aftermarket/faq/

Look at questions 2 and 3, they still don't state exactly what the modifier does....Hmmm.

EdmontonSS

Bringing this back again... I tried to do some research on "friction modifyer", half of the references say it makes the oil "sliprier" (sp?) and half claim it alows clutches and cones to "grip" also there was a refrence that GM modifyer works differenty than other modifyers, some my increase, some may decrease "slipriness". NONE of these sites were definite nor had any technical discussion on the fact. Either way, it may be an idea for those experiencing shifting problems to atttempt to some GM friction modifyer, before changing out $50 or more dollars worth of fluid... But does ANYONE know for a FACT what GM modifyer does???