I have a 1988 Suzuki Samurai. The manual transmission shifts up fine, and downshifts into 3rd and 4th fine. When in forward motion, it is difficult to downshift into second, and impossible to downshift into 1st without double-clutching.
It does not grind, and I can hear the transmission spin up when 1st is attempted, but the shift never completes, unless the vehicle is stopped or rolling backward, or the double-clutch technique is used. 2nd is similar, but it sometimes completes the shift.
When stopped or rolling backward, 1st and 2nd shift fine.
I currently have Amsoil Manual Transmission and Transaxle gear lube in and that helped shifting some.
I am wondering if Auto-Rx has been known to restore syncronizer effectiveness in cases like this.
Hard to say. Downshifting into 1st is typically not done by most. 2nd is used until the car comes to a complete stop. I've used it in the past, but I don't fast and furious like I used to. The Amsoil manual lubes are about the best that there is, imo, but no harm in trying Auto-Rx to see if it can be improved upon.
I typically do not downshift to 1st either, but when you hit a 25% grade up in the mountains, and have to make a 15 mph hairpin, you need 1st when you are only playing with 63HP and 75Lb-ft of torque.. That is just one occasion when it is required. There are many other occasions when 1st is needed without coming to a complete stop, when you go off-road and/or play in the mountains.
Every other manual transmission vehicle I've owned would do it. I'm sure this is a wear-issue, but am hoping to get away without having to rebuild the transmission, at least this year...
I put some left-over Auto-Rx in. No change yet. We'll see. I can always double-clutch.
Sami's are great offroad. Love watching those things. Give it a try and see what happens. Does it currently grind or just not engage without double clutching??
No, it does not grind and it upshifts into second smoothly, and also shifts smoothly into first if stopped or rolling backward.
I can even hear it spin up the clutch as 1st is requested. It just won't complete the shift, even at 1mph. Has to be completely stopped or rolling backward.
I would be surprised if you can get that synchronizer back to new condition again. The fact that it is not grinding is good, however. I have new synchros in my truck gearbox and I still double clutch while downshifting, to take the load off the synchros and hopefully make them last forever. Also using MTG, which made it really shift like new.
Thanks. I now have gone 600 miles since putting the AutoRx in, and have felt very little difference.
I've resolved myself to having to double-clutch for 1st and 2nd. No point in rebuilding it when everything else is working great...
I've since used the rest of the leftover RX in the rear diff and transfer case, which are now leaking, probably due to the cleaning effect of the synthetic. I'll be putting conventional fluids in at the end of 1,000 miles to hopefully restore the seals.
-- Edited by VaderSS on Monday 21st of June 2010 01:58:21 PM
Do you have any update for us VaderSS? Are you sure that 1st gear is synchronized in the first place? I remember some trannies back in the day that didn't have synchronization for 1st gear.
Did your seals stop leaking in the T-case and rear diff yet?
Seals are still leaking, but not as bad. I need to switch to dino oils and see if that stops the leaks.
No change on the syncros. 1st is syncronized. If I am rolling backward, I can shift into first easily. If I push toward 1st, I can hear the gears spin up, so the syncroniser friction portion is fine, it is the part where it meshes and lets the gears mesh that is not working, and only then for downshifts. Upshifting to 2nd is no problem.
I have developed a work-around for downshifting to second where I tap the shifter toward first for a moment, and then drop it back to 2nd. This speeds the gears up and tricks the transmission into thinking it is upshifting. I still have to double-clutch to downshift to 1st, even if I am barely moving.
I feel that the syncro action has improved from the rinse application, though only marginally, and not enough to restore proper functionality to the transmission in 1st and 2nd.
The seal leaks that synthetic oil caused have been greatly reduced, though not to the level that they were at before changing to synthetic. The cleaning effect of the rinse oil in all units has been tremendous. Within 2,000 miles, the rinse oil in the diff, t-case, and xmission were black. None of the initial oils, nor the Auto-Rx treat oils, were near as dirty as the rinse oil.
I am planning to Auto-Rx all 3 units again. I don't expect much, but you never know...
-- Edited by VaderSS on Monday 6th of December 2010 12:25:57 PM
