164 synchro grinding

Grant · #1 (**permalink**) 11-03-2009, 06:51 PM

Hello,

Our 164LS (85K miles) has had a grinding 3rd gear ever since we've owned it (last couple of years).

Receipts say there is Redline tranny fluid in the transaxle right now.

The interesting thing is, when the box is cold, 3rd acts completely normal...no grinds from reasonable shifting. As temps start approaching normal, 3rd gear basically needs to be double clutched in both directions to avoid a grind. I've gotten to the point where I can get it to engage quietly most times, but it's still a little annoying. It's a nice car otherwise.

Is there a thicker or thinner tranny fluid I should try? I'm hoping to find something that will have properties more like the colder tranny fluid to at least help 3rd gear.

Any tips?

**dennism** · #2 (**permalink**) 11-03-2009, 07:51 PM

Grant, The owners manual for my 1991 164B specifies Dexron II or equivalent, if I remember correctly. That would have been the best grade of Dexron available at the time(1991) I suppose. There is now a Dexron III.

I have used Redline Synthetic Racing ATF in my car, mainly because it was the only type I could find to buy where I live. It works fine for me.

Because I had some, I've been adding a small amount of Moly to the fluid as I put new in, sort of as an insurance policy. The transmission shifts very smoothly, and is quiet.

The car has just gone by 240,000 miles, and it is the original transmission, except for the change to a better input bearing, done by the PO over 100K ago.

I try to shift smoothly, and not in a hurry, which involves an almost imperceptible pause between one gear and the next, sort of a double movement - out of one gear, then into the next. I do not double clutch, except when downshifting.

Hope this helps you. Dennis M.

**mac2444** · #3 (**permalink**) 11-03-2009, 10:01 PM

Grant, I'd be tempted just to drain and fill with new Redline ATF. It'll at least give you a chance to see if there is any metal in the fluid so you'll know if you should stop driving her till you can take it apart. For $25 it can't hurt. I've had good success with redline in the past and most people on the forum seem to as well. Jason has mentioned a couple of good alternatives fluids in one of his posts as well.

Good luck, Graeme

Grant · #4 (**permalink**) 11-03-2009, 10:16 PM

I keep seeing mention of ATF...this is to be used in a manual transmission car?

**Gubi** · #5 (**permalink**) 11-03-2009, 10:18 PM

Yep, that's what they spec for the 164 5-speed. Dexron ATF.

Grant · #6 (**permalink**) 11-03-2009, 10:22 PM

Any idea if a thicker fluid would help me?

**mac2444** · #7 (**permalink**) 11-03-2009, 10:47 PM

I don't know if there are much differences in thickness of Dextron III's. Some do cling to the parts much better than others but that's why many switched to Redline in the first place. If you go to a manual gear oil I'm sure you will have more options but you will be a bit of a test pilot and may run into much bigger tranny issues than with the ATF.

**Alfisto Steve** · #8 (**permalink**) 11-04-2009, 04:09 AM

I have a 93L with 3rd gear syncro crunch, too. Until I fix it I just have to slow down 2-3 upshift. I now use ATF in tranny but was going to try 80-90w GL4 before I pulled tranny to see if that helps until fixing time.

**dennism** · #9 (**permalink**) 11-04-2009, 08:49 AM

Further to Graeme's post above, there is a magnetic plug in the case. It's up above where the bottom drain plug is. Maybe Steve can show you with a pic.

You might try pulling it to look for chips, and to clean them away. Good luck.

**Richard2** · #10 (**permalink**) 11-04-2009, 09:31 AM

My now deceased black 164S ran ATF all of it's life. 167,000 miles.
The silver 164B came to me with 130,000 miles and gear oil in the transmission. I decided to switch to ATF and got a lot of leaks so switched back to ATF. Both transmissions shift smoothly with ATF or gear oil.

Michael Smith · #11 (**permalink**) 11-04-2009, 07:58 PM

These transverse gearboxes do not like heavy gear oil. There are no high load gear face contacts in these boxes. The reason ATF works so well is the gears are basically loaded like planetary gears in an autobox.

Usually it is a big mistake to deviate from the exact lubricant specified by the manufacturer. The boxes are all splash lubricated and viscosity affects this lubrication quite a bit.

**Alfisto Steve** · #12 (**permalink**) 11-05-2009, 06:19 AM

My B model came to me new from the factory with gear lub not ATF. I switched over to ATF at 130k when I had to replace noisy old style ball bearing input shaft bearing. Still using ATF and no noise.

My 93L came to me used with gear oil (maybe to reduce noise) It now has ATF but is a bit noisy even with new style roller bearing that was in box when I bought car with a blown clutch throw out bearing. It is the one now with crunchy 3rd gear syncro.

**Alfissimo Int.** · #13 (**permalink**) 11-05-2009, 07:31 AM

Quote:

Originally Posted by Michael Smith

These transverse gearboxes do not like heavy gear oil. There are no high load gear face contacts in these boxes. The reason ATF works so well is the gears are basically loaded like planetary gears in an autobox.

Usually it is a big mistake to deviate from the exact lubricant specified by the manufacturer. The boxes are all splash lubricated and viscosity affects this lubrication quite a bit.

**Alfisto Steve** · #14 (**permalink**) 11-05-2009, 07:40 AM

Point of info on RWD and FWD Fiat and Lancia (Fiat) trannys in days gone by (70-80s). The manuals called for GL1 mineral oil even in the X1/9 and 128 transaxles and not GL-4 like Alfa called for in RWD Alfas.

I found some 75-85w gear lub without EP additves I think I will put in Rosso 93L and see if that helps quiet down the old girl and keep using ATF in my B model with quiet tranny.

Michael Smith · #15 (**permalink**) 11-05-2009, 06:41 PM

The 91 Alfa Romeo shop manual specifies Shell Dexron II or AGIP Dextron II for both manual and automatic transmissions. One assumes the extra T is for the Italian 8-)