JFD_8126

iTrader: (5)

Hey all,

I just joined the sa22 boat just today. Got a 1979 Mazda rx7, big con, it's auto. I believe I have the 3 speed auto tranny but for some reason it does not want to go to the 3rd speed while driving. I verified that it goes to the 2nd speed. I really hate it. Can't drive on the freeway since going at 65 mph at 4500rpm+ really is annoying unless that is normal and I am getting the 3 speed info wrong. Can anyone help on how to fix my problem??

Thanks

t_g_farrell

iTrader: (1)

Not many folks are up on the auto. I know I don't know the normal shift points for an RX7 auto tranny. You might want to look it up in the FSM or try a search on here for it.

DivinDriver

iTrader: (15)

General first actions for any auto tranny that's showing failure in shifting or slippage, is to make sure the fluid is up to proper level, and if that's OK, change the fluid and filter.

Check the fluid on the dipstick; if it smells burnt, replace it and the filter.

Never worked on an RX-7 auto trans, but dealt with several other brands from that period. Clogged filters, low or burnt fluid, both common causes of trouble.

JFD_8126

iTrader: (5)

Hey thanks to you both responding. I believe my transmission IS functioning properly.

Can anyone please verify.....

***1st Speed*** ***2nd Speed**** ****3rd Speed *****
idle ----------> Shift1 ------------> Shift 2 ------------------->


I believe that's how a 3 speed automatic transmission works.

IF that is the case, i need to switch to a 5 speed manual tranny soon. LOL.

I'm actually considering getting a donor car to purchase and just swap from there, but money is my issue currently.

Thanks,

DivinDriver

iTrader: (15)

Yes, with a three-speed auto, (aka, a 'slushbox') you'll only feel two shifts. When idling, you are already in first gear, but unclutched. You start rolling as RPMs pick up and the torque converter starts transferring power, then the first shift takes you into second gear. The second shift takes you into third gear.

Per the 80 FSM tech data section, heavy throttle shift speeds should be:

D1->D2 = 32-45 MPH
D2->D3 = 59-77 MPH

At half throttle; upshifts should occur between 9-21MPH and 18-40MPH

Acceleration kickdowns are 3->2 @ 51-65, and 2->1 @ 14-30

JFD_8126

iTrader: (5)

Hey divindriver,

Thanks for so much info. That really made me relieved that I don't have to swap trannys anytime soon. Thanks again. I hope this thread helps others who has similar worries as me.