Any auto transmission mechanics out there?

[spidernut]

Anyone here an auto transmission specialist? I have a TH180 question on my Spider.

[bradartigue]

It is a GM transmission. 3L30, TH180 Hydromatic. An automatic transmission shop should be able to service it. It was used on a bunch of cars:

http://roadkillcustoms.com/Hot-Rods-Rat ... z3grRzxa00

[spidernut]

Brad...you'd think so but that doesn't seem to be the case thus far.

Example: I called a local shop with a great reputation - I asked him if they were capable of servicing a 79 Fiat Spider with a GM TH180 hydromatic transmission. I explained that it is the same one used in many GM cars, Opels, Fiats and a Chevette (I forgot to mention the Geo Tracker). First he asked me if it was front wheel drive (O.K., that was a fair question if I had a Geo Tracker, but not a 79 Spider), and then he asked me if it was a manual transmission. Sigh.

I obviously have more calls to make.

[bradartigue]

Hey I just go by what I'm told...but it was a very common transmission in the day. If you call and tell them you have an auto transmission from a Geo Tracker and bring that do them, they'll probably fix it. You said "FIAT" and they ran away like babies.

The best service for an AT Spider is to remove the AT and throw it in a river. The car was never meant to be driven with only two pedals.

[ORFORD2004]

The best service for an AT Spider is to remove the AT and throw it in a river

Greenpeace will put a reward on your head.

[seabeelt]

John, what's wrong with your car? Knowing your skills through the forum, a rebuild kit is not out of your league I would think.
R/

[spidernut]

Auto transmissions are way out of my comfort zone. I've removed the upper and lower valve bodies, filters, made adjustments, etc., but this out of my league. I know my limits and auto transmissions are very foreign to me.

The car runs fantastic, shifts fantastic and everything seems to be just sunshine and roses - and then you listen to the transmission and you get a different impression. I've owned this Spider for 15 years and it has had a rattle that I have tried to located for 15 of the 15 years. I wouldn't worry about it normally (it is an old car), but it seems to be worsening.

I have isolated the noise and it is definitely coming from the transmission. It sounds something like a tin can with a few marbles rolling around in it. It reacts to higher RPMs and not to higher speeds, so that means it is in the front half of the transmission.

1. In neutral or park, the engine revs and is as smooth and quiet as can be at any RPM
2. When in 1st gear, it is smooth and quiet to about 2,400 RPM (tested with the car elevated in gear) then there is a light rattle worsening up to about 3,000 RPM
3. When in 2nd gear, it is smooth and quiet to about 2,400 RPM and there is a significant and highly noticeable rattle which gets worse at higher RPMs
4. When in 3rd gear, it is smooth and quiet to about 2,400 RPM and the light rattle is about the same as in 1st gear

I think that would indicate that it has something to do with 2nd gear. If it was the torque converter, it would rattle the same in every gear. I'm guessing something internal.

I did consider just pulling the automatic and swapping it with a manual since I have a spare transmission, drive shaft, clutch cable, and a few other misc parts in my garage. I'd still need a flywheel and good speedo, but that's pretty easy to find, so converting is not off the table. Most of my driving in the car is in town or in straight lines on the freeways. After switching back and forth between my son's manual and my automatic, I realized that I really do like the convenience of the automatic transmission. It is WAY more fun to drive on short trips and in town. When I drive on winding roads or look at my gas mileage, I really miss a manual.

Still, I'd like to keep it stock but need to find an expert that won't hose me for the $1,400 - $2,000 they want to rebuild the tranny.

[seabeelt]

How about a junk yard donor for a couple hundred bucks

[seabeelt]

Is t most of that cost taking the tranny in and out. What if you just took them the tranny

[seabeelt]

Complete rebuild kit from rock auto $112 Includes just about everything looks like There must be a manual to be found somewhere

[spidernut]

I used every extension I had, u-joints, etc., and can't get to the left top bell housing to block bolt at all. The rights side is slightly better, but not by much. I believe I'd have to disconnect the drive shaft, and tilt the motor and trans down. The older I get, the less I like pulling transmissions....especially automatic transmissions which are insanely heavy.

[seabeelt]

I hear you, an nothing's ever easy, especially on an old car

[Nanonevol]

I hesitate to suggest this because I know it's do-able but if one had no alternative to get that top left bolt...

This is the spot.

[Warren]

John:
The Fiat Spider factory service manual available from International Auto Parts has a complete section on the TH180 transmission rebuild. It is discouraging to look at it as it is has a lot of pictures and it looks like there are hundreds of very small parts. I have rebuilt several manual transmissions but never tried an automatic.

[spidernut]

Warren - I looked through my Fiat manual at the same section and decided it is just too much to do myself. I'm always up for a mechanical project but not this one.