supergerman

I bought a 91 convertible with a auto tranny and a 13b motor...
seems that the tranny is slipping, the question is, would a regular mechanic be able to raplace the tranny on this car? or is it different because of the rotor motor? will I have to go through a rx7 specialist only?
what about some one like aamco?

what am' I looking at here problem wise / $$$ ?

Aaron Cake

iTrader: (1)

Nothing special about the tranny or replacing it. Any mechanic should be able to do it.

Not sure on cost, but I would imagine that used auto trannies are DIRT cheap as no one wants them...

supergerman

why don't people want them (aside from not being as fast as manual)?

also, is the slipping causing the car to waste more gas? or are these cars gas guzzlers as is..?

RoninAutoBoX

Don't give up on it yet. My autobox was making my car run like **** until I had the fluid changed. I am running B&M Trick Shift fluid, and it turned a shitbox that would only start off the line in 3rd gear, into a solid redline performer.

Aamco once said that if everyone changed their ATF when they should that they would go out of business.

BTW, the autoboxes are not cheap to find either. The Mazda MPV and the early 929s share our trannies, and they are still in reasonable demand.

RoninAutoBoX

Get that trans filter changed too. It will likely be full of gunk.

Aaron Cake

iTrader: (1)

Most people don't associate sports cars with automatic transmissions. Yes, RX-7s are gas guzzlers.

I have lots of auto trannies sitting around gathering dust. People do conversions from auto to manual all the time.

Dan H

I agree, check filter and change fluid. My 2nd guess will be most likely the torque converter is the cause of the slilpping.

supergerman

ok, how the hell do I change the filter and the fluid? I have zero knowledge about these cars, or should I just take it in to a mechanic? what am I looking at $$$ and same thing if it's the torque converter / autobox?
or would it be just easier / cost effective to throw in a used tranny altogether?

Aaron Cake

iTrader: (1)

Get the Haynes manual and read up on transmission service. Lots of good info. Changing the filter and fluid is not that hard.

Changing the torque converter is about the same labor as changing the transmission, as in both scenarios, the tranny must be removed.

supergerman

so you mean that in order to change the transmission fluid I have to remove the tranny itself???

Rob500

No he didn't say that. You can probably change the fluid and filter for $50.00 The torque converter probably did not fail. If the trans is slipping it is probably the clutches. A trans rebuild will cost in the neighberhood of $1000.00.


Rob

wam

hey, im a automatic transmission specialist, the 91 tranny you have is electronic. the are very hard to find, but the ones out of a mpv or a 929 will work but you have to change bell houseing... these trannys and torque converters are very weak in all of these rx-7s... they dont like abuse... and a extra tranny oil cooler is a must for these cars..heat will kill these trannys fast!! what is the tranny doing, and maybe i can give ya some pointers!, but if you will keep these trannys cool and not abuse the to hard, they will last! btw.. they are a JAPCO tranny... the same ones in nissan 300zx also..and some jap small trucks!

supergerman

when it hits around 3000rpm, the shifting either kicks in kinda hard from first to second and second to third..or...its revs up higher then kicks in, but if I ease of the gas when I feel it should be changing gears then it shifts smoothly...though, that is a pain in the *** when I have to get on the freeway, as I can step on the gas to get to freeway speed without slowing some of the other cars behind me down...

c-squared

Actually, its a Jenco, to be specific.

Usually, when the clutch packs/bands start slipping, it has been from negelect in following the routine transmission sewrvice schedule. A simple fluid change will liklely not solve the problem. I suggest simply swapping to a used transmission.

Your only realy available modification for these transmissions is a fluid change. There are two decent brands, and of the two, B&M trickshift has better results, but expect to pay for.

For longevity, B&M makes some really good coolers and external filters. You should definitely change over to a fluid/air type transmission cooler, as opposed to the stock heat exchange system (works on the principal that coolant is always colder than tranny fluid, and heat will diffuse through the radiator side tank into the coolant).

You best bet for auto tranny longevity will come from frequent fluid changes, every 2 years or area.

hypntyz7

For my 2 cents, Im not a transmission specialist, and dont know jack about them, and furthermore dont want to learn. IF I encounter a bad one, I swap it for a known working unit or convert to 5sp.

EVERY auto transmission 2gen I have been associated with in the last 5 years has had shifting, slipping, or gear loss problems within 1 year of the first time I saw it. True, most of the problems lie from abuse and lack of maintenance, but at this point almost ANY used auto tranny you get will be within a year or 2 of the end of it's life. Even when they're right, they dont shift smoothly like the ones in most other automatic cars; when you want them to rev out, they short shift, and when you want them to shift smoothly, they jerk into gear too hard, and when you want them to downshift, you can hang that in your *** for about 3 seconds.

Bottom line, either find a *reputable* tranny man that will stand behind his work, or go on and plan on changing used trannies every year or 2.

****, I bought a car with a tranny rebuilt with 700 miles on it, and sold it to an admin on this forum. About 10 months later, or 10000 miles I guess, he informs me it went back out.

The autos in these cars suck *** man, Im telling you from experience. Theyre a bitch to work on, they dont hold up well, theyre damned expensive, theyre hard to find in tested working condition (I just threw an untested one away), theyre heavy, theyre not smooth (the whole point of an auto trans) and they make the car slow.

NZConvertible

It's not JAPCO or JENCO, it's JATCO, as in Japanese Automatic Transmission Company.

wam

sorry thats what i ment to say!

supergerman

what about one of those ''ship trannies''?
you know which one, the ones which are taken out of japanese cars over there at around 40-50 thousand miles or so (due to the strict smog laws) and sent over here, (same as with engines) from what I know, they are pretty good, since the japanese have to have them serviced when they have to be, and wether or not the engines' trannies are good or bad, they have to be replaced within that 40-50 k miles on them..

found a place which tells me that they will do the whole job (including the price of the tranny ) for less than $700, (is that pretty good? sounds to me like it is..) plus another 100 bucks if I want to add the second oil cooler, (which I have to ask, can the cooler be added later on? or does it have to be wehn the tranny is changed?)
??

Dan H

For $700??

Assuming you do your own work, I would go do a manual conversion. Up to you if its worth it to you or not.

supergerman

I wouldn't even know where to start to do a conversion, but anyway, is that 700 dollar price high or low to switch over to another auto tranny?

btw..they give a 3 month warranty on the ''ship tranny''...

Rob500

Have you actually determined what the problem is? There are many causes for auto trans problems (elec, vac, low fluid, etc). Find out what the problem is first. I wouldn't pay $700 to put a used trans in my car. Even with a 3 month warranty.

Rob

grinchy

There's a Rotary shop in Gardena that would be able to do the auto -> manual swap for you, probably for that price.

supergerman

grinchy, can you tell me exactly where that shop is at?

Rotorific

iTrader: (1)

update this post..... I have a question concerning auto swaps.... Ive found the specific years of the 929 tranny you can use...the question is can you use an auto out of an FD because the 929 and MPV use that very same tranny as well for the corresponding years (93-up)