i have an 84 with the doug nash 4+3 riding the other day i heared a bearing noise and od kept kicking off and on so i checked to find out that the atf was low due to a leak around the pan so ifixed that drove 2 miles and the noise went away . but i had no OD got home now the car has no reverse forward gears are fine except no OD . reverse tries it rocks bask when you rev the car up in the reverse gear. not sure what to look for or where to look at, thanks for any help!!!!

 

I have an 88 4+3 and I had the overdrive transmission fluid changed this year (at 31000 miles and I think the book says at 30000). I just mention this in case your car is the same, adn you didn't know the overdrive transmission fluid is in a different place.

 

He's right. Your OD tranny fluid may also be low.

 

Use the OD for long highway rides only (more than a couple miles). Remember to turn it off when exiting the highway or the trans may act a little funky.

 

Sorry 500 Horse. Didn't mean to attach that to your post. Oops.

 

I had the same problem about a year ago - the no reverse problem if I remember correctly was a due to a failed slave cylinder and/or failed master cylinder.

 

Sorry, but it sounds like you are the owner of a boat anchor(OD unit)
http://forums.corvetteforum.com/show...o+reverse+gear

 

correct...OD unit may be shot...time to replace...before you do ANYTHING else, call Bryan at S-K Speed in NY...631-957-9427...describe your problems to him...I replaced my OD unit through them and they are the MASTERS of OD units.

How handy are you with twisting wrenches? if you have reasonable skills and plenty of patience, tools, a transmission jack and a good friend, it can be done in a garage. (you can also paint a vette in a garage with AMAZING results (ask me) but thats for a different thread)

Some General 4+3 advice...as mentioned before, ONLY use it on the highway (over 55mph)

Always use the clutch when switching the OD on and off, just like you were shifting with the stick

RELIGIOUSLY change the OD fluid and filter every 10K...it just as easy as changing the engine oil...Eckler's gives you a new grommet with the filter kit, so go with them (I order 2 at a time in case a the grommet or filter mess tears on installation)

There is another transmission that uses the exact same filter and some Autozone's carry it, but i can never remember the year/make/model of that other car.

I use a bead of RTV around the OD pan to form a gasket instead of using the paper seal. They notoriously leak anyway.

Be VERY careful not to cross thread the 10mm bolts holding the OD pan on...its REALLY easy to do.

make sure that there is a magnet in the OD pan to catch the particles. Remember, its essentially an automatic OD unit, so it does burn off bits of clutch discs.

I'll keep checking back on this thread if there are other questions.

 

i also heard that i could be sucking air around the filter and do i check the fluid with the car running or what ? thanks again!!!!

 

If reverse gear engages fine your clutch cylinders aren't an issue.

Sounds like you fried your overdrive unit. This is interesting because the low pressure switch in the pan is supposed to shut it off and protect it if it's sucking air. Adding fluid won't fix it now.

Is this a low mileage car?

 

yes, the car only has 72000 miles. i would like to put a t5 in but dont know what or if it will fit. like the lenght and the yolk spine. dont know if i should get it rebuilt or try and find a t5 somewhere. thanks !

 

I wouldn't do the T5 unless you want to be the first guinea pig to do it. I've never seen it done on a C4.

If you want to upgrade, consider the 89-96 ZF6 or a Tremec TKO.

TKO kits are sold by www.KeislerAuto.com and www.ClassicChevy5speed.com

ZF6 is the best and cheapest choice, IMO.