1983 Celica-Supra P-Type, 38K miles. Garage kept, never abused… I have a really hard time shifting into 4th gear. Rebuilt clutch master & slave, adjusted pedal. Buttery smooth 1st-3rd. 4th does not grind but requires a lot of force to shift. 5th shifts ok, but feels vague; hard to tell it’s in gear.
Have you checked transmission oil level?
Synchros . . . ?
Yes. Clean and full AMSOIL 75w90 GL5. Changed anyway.
With a car this age the linkage can get worn and out of adjustment. That’s what I’d check next.
Doubtful. Does. Not grind one bit.
Maybe something is under the boot by the shifter, or clogged up by debris etc. PS a friend had one of a similar vintage we did some touring in, great car!
GL5 may be damaging your transmission. Although your immediate problem is likely a synchronizer or the intermediate bearing problem unrelated to the oil GL5 is a rear/drive axle lubricant and is a blend that deteriorates synchronizers. Is there a whining noise when idling in neutral with the clutch released?
Solved. Shifter knuckle bushing cracked.
Good that its solved but I think you should check to make sure the fluid is approved by Toyota. I don’t know much about GL5 vs GL4 except when trying to get the right stuff for my snow blower, but I do recall an issue with the one not being compatible with some bearings. So I’d get the stuff from the dealer to make sure you’ve got the right stuff.
Have the original owner’s manual which specifies GL5. Also spent 10 years in the service department of a Toyota dealer. We use this fluid in all of our cars without issue. Thanks for your response.
Well that answers that issue.
Not all cars use GL5 in their trannys. Toyota’s older W50 5 speeds specify GL4.
If you search for the phrase GL4 vs. GL5, you’ll find that GL5 is reported to damage brass synchros.
Just curious, where is that part located? Under the shift lever? Or on the side of the transmission? Or where?