Car: 1986 Mazda RX7 N/A

Every morning i drive my car to work, and everytime I downshift into 2nd it doesnt really wanna go. Usually i push the shifter a little bit closer to 1st and ram it into 2nd then it'll work. But after downshifting into 2nd say 5 times it works like it should. Whats up here? All i can think of is the bushings, transmission fluid change, or maybe put in some Lucas transmission fix?

 

Hello?

 

My 88 GXL has the same problem. I believe its a bad syncro. Do you also grind 2nd sometimes when you shift from 1st even if your clutch pedal is to the floor?

 

if thats not the case then a bad shifter bushing???

 

Sounds like a worn synchro, try a friction modifier, for example something from Red Line or change the gearbox oil, maybe Red Line shockproof. The oil may be a bit expensive, but cheaper than possibly rebuilding the gearbox. I know it stopped my gearbox crunching, etc.
But I may be wrong...

 

rev match and you might not have that problem

 

+1 Jizneremie33

Atleast revmatch if your downshifting, you may also want to try double clutching. If neither help any then your syncros aren' t the problem

 

Ive decided to just do a tranny fluid change. Gonna take me 3 quarts so im probly gonna get 2 quarts of redline or royal purple and a quart of lucas transmission fix.

 

Nope just 2nd..

Seeing as it only really does this when its cold, it could be low on fluid.

 

Mine does it sporatically, but I blame it on old tranny fluid

 

You shouldnt be forcing anything. Great way to **** up a transmission fast.


If it doesnt want to downshift then try rev-matching (you should be doing this anyway)

If it still is being mean that try double clutching (im of the opinion that if you are downshifting to a high rpm you should be doing this anyway)


In either case just forcing it into second gear is a good way to **** up the whole thing and get yourself a rebuild.


BC

 

How do you double clutch a synchro based transmission. I do believe double clutching was bad in the old days when you'd press the clutch pedal once to disengage the clutch, match the revs to the speed of the car, shift, then press the clutch again to engage it.

Either that or someone lied to me. But IMO maybe you or someone else may be watching too much FntF.

 

You can still double clutch in trannys that has syncros.
It will make your shifts more smoother if you do have bad syncros.
you clutch in, shift to neutral, clutch out, gas, clutch in, and downshift.

I had to do it so many times in my brothers 240 where it would sometimes be a bitch to downshift to 2nd, but I mostly heel toe though. Driving his car actually taught me how to do heel toe because of the tranny problem LOL

 

....... The same way as you just described.

Long story short this helps to get everything up to relatively matching speeds and makes the synchros do as little work as possible. As opposed to going from third to second at 55 pmh and just jamming the shifter into second. Or just clutching in, rev matching, and then cramming it home. When you let the clutch out in neutral then rev up you bring the input shaft and clutch up to speed as well. When you just rev match with the clutch in the synchros still have to bring the clutch and input shaft up to speed. Not NEARLY as bad on them as asking the synchros to bring the engine and flywheel up to speed as well, but not as easy as bringing everything to within a couple hundred roms of each other.

You dont HAVE to double clutch, but wearing the clutch out a little faster is cheaper than rebuilding the tranny because of synchros. Any downshifting I do is double clutched. Even at deals gap. The only time I wont do it is if I come in too hot and dont have time. Otherwise the fraction of a second that I waste is inconsequential to me. Im not trying to impress anyone with my times through DG.


BC