81 Zagato Stiff Shifting

[Allen Lofland]

The 81 Zagato is difficult to get into first and second gear when
you first start it up. It doese not grind, it is like a linkage
difficulty. But as it warms up and is used it gets easier. I
suspect the notorious linkage bushings BUT if that is the
problem, why doese it seem to imporve as it warms up ??????
Is this typical of bushing failure or should I look at
something else like synchros. BUT there is no grinding of gears
both up and down shifting...???????? Thanks O forgot, I drained
the PO's mystery trannie fluid and re-did with Mobil Synthetic with NO
noticable difference :)
Thanks

[Hamish]

You could try having a look at the the top connector at the front of the linkage where it connects to the gearbox, this can be adjusted and you might get a better quality change :wink:
It is also possible that the shift is fouling the thermostat (assuming American market models are equipped the same as UK/Europe models are :?: ) so have a look on the thermostat housing for wear.
I have fitted a linkage kit - came to the UK via Bayliss I think - and it really has improved the quality of the change.
As an afterthought, have a look at the shift links where it 'disappears' into the front bulkhead, these can seize up so it might be an idea to overhaul the whole system with lots of penetrating spray first.... :?:
Good luck :!:

[peter_coupe]

You better check oil that you are using, Mobil Syn..

Italian early gboxes need good conntact metal to metal to work properly, many people ruined gears and synchros by using wrong gear oil.

When I rebuilded my gbox I paid 120AUD for 4L of oil.

Peter

[Allen Lofland]

Peter: How many US dollars is 120AUD for 4L of oil And what did you do with 4 leters of oil, it wont hold that much :)?????
Did your gear shift hard till warmed up i???????
Thanks for the responce

[Will]

The syptoms you describe sound like the classic issue with motor oils not having the correct coefficient of friction. Although the Mobil 1 you mention has an acceptable viscosity, your notchy cold shifting problem would likely be solved by draining thoroughly and using Redline MTL or GL-4.
This will run you $9-$11 per quart on average, you'll probably need three quarts. Although the stated spec on my scorpion is under two quarts (1.67L) the box actually takes about 2-1/3 quarts to fill to indicated levels.
I think this may be because the capacity is a "refill" not total capacity, and I drain better than the guys that made up the shop manual.
At least, that's my guess.
-Will

[DJ]

Actually, I'd guess (and it's only a guess) that you MIGHT have a dipstick from another car, Will. I had one incorrect dipstick in one of my cars and what I believe to be the correct one in the other. With the one I believe to be correct, the recommended amount of oil filled it perfectly to the correct indicated level. And this was after I had the tranny apart and replaced the differential so I'm quite sure it was completely drained.

Jim Fierst apparently blew seals on his tranny because he had an incorrect dipstick and too much oil. Not exactly sure how that happened but it did more than once on his car so I'm pretty wary of putting more than the recommended amount in.

Will's recommendation of the Redline oil is spot-on. I use it now too and it makes a huge difference in shifting. The newer hypoid types of oils make the tranny really tough to shift. The spec calls for GL-1 but it's hard to find around here. Some farm stores apparently carry it for tractors but you normally have to buy it in a minimum five gallon quantity.

The specs also list SAE 40 (NOT a multi-grade, just SAE 40) motor oil as acceptable but Chris Obert has stated in the past that more recent service letters from FIAT recommend against this because of excessive wear observed in some cases. I used it as an interim solution on my red car just to see if it made a difference while I was waiting for the Redline to arrive and the improvement was IMMEDIATE and significant. In fact, I believe the tranny shifted a bit nicer than it does now with the Redline. However, the Redline is also a vast improvement over the hypoid oil it had in it and is highly recommended in my book.

FWIW

[Allen Lofland]

Hamish : Your a genious,,thanks ever so much. I removed my t-stat today and the shifting problem vanished :) AND the t-stat has a very bad wear spot on it's back side :(
It is obvious after looking in there good and takeing the back short hose of that some one in the past as repaired a end leak by shortening the hose and there bye bringing the t-stat aft to meet the shifter. You got it right. Now I can shift easy.
Will soon get a shift kit and some MTL for the fast shifting :) Thanks Hamish

[peter_coupe]

I duno 120 Aud may be 80-90 US.
Gearbox takes 2 l of oil so I have one more change from the 4l, it did not come less then 4l package.

I rebuilded my gbox, it took maybe 1000km for all parts to bead in, now I don't have any problems. It goes very quickly into the second without any noise, the trick I use is to always before moving shift 1st-2nd couple of times and then engage.

I do quick shifts in to the 2nd at 5000rpm, it is smooth ( so far)

ciao

[Hamish]

Hamish : Your a genious,,thanks ever so much. I removed my t-stat today and the shifting problem vanished :) AND the t-stat has a very bad wear spot on it's back side :(
It is obvious after looking in there good and takeing the back short hose of that some one in the past as repaired a end leak by shortening the hose and there bye bringing the t-stat aft to meet the shifter. You got it right. Now I can shift easy.
Will soon get a shift kit and some MTL for the fast shifting :) Thanks Hamish

You're very welcome :oops: glad I could be of help :wink: