T-5 Downshift Problems
02-21-2006, 12:45 PM
#1
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Car: 89 Firebird
Engine: 5.7 TPI
Transmission: 5 speed
Axle/Gears: 3.73
T-5 Downshift Problems
My T-5 will not downshift from 5th to 4th or 5th to 3rd. It needed a clutch so I installed a new clutch and all new hydralics. Still having the problem. If I downshift the 2nd them up shift to 3rd or 4th it works fine. There is no gridding or funny noises coming from the trans. Does it need to be rebuilt? Anyone have any ideas?
Chris
Chris
02-21-2006, 10:01 PM
#3
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Car: 89 Firebird
Engine: 5.7 TPI
Transmission: 5 speed
Axle/Gears: 3.73
No it does grind. I did try to RPM match and did the same. If I take it out of 5th I can put it back in 5th.
02-22-2006, 09:47 PM
#4
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Car: 91 Z/28, 89 RS Race Car
Engine: 305 stock / ZZ4 AFR 195 9.7:1
Transmission: T5 / t10 / Jerico
Axle/Gears: 10blt w 3.42, 9 in w /3.80 DL
Try to swap out the transmission for a rebuilt one.
The syncros are gone. They need to be replaced. It is a real bitch to get to the 3rd gear syncros and get them off.
If you do the job yourself you are going to need a press to get the 5th gear of the shaft so you can get to the 3rd gear syncros. Heat the gear or you may break it in the press as I did.
How am I so sure? Did it twice and did not replace the 3rd gear syncros the 1st time.
Here the problem, the syncros match the shaft speed and the sliders lock shaft to the gears via the syncros. (Call the dogs in a non syncro unit). The gears are in constant mesh but free wheel on the shaft until the syncros engage and lock them to the shaft. In order to lock them to the shaft they have to be spinning at the same speed. Where the syncro rides on the shaft it has a friction material like a brake lining which makes it want to stick to the shaft and spin at the same speed. When this material wears off, the syncros will not do their job and you can not down shift the unit no matter how hard you try. The shaft is at one speed, the syncros are at another and the gears are at a third speed which is slower because they are still being spun at the shaft speed for the higher gear that you are trying to come down from.
When you take it apart you will understand how it all works.
THe cause for the damage is due to not using proper heel and toe downshifting and using the trans as a brake. This burns off the friction material off the syncros. The syncros of the upshift see little wear because the trans is not being used as a brake and the syncros are not being used as break shoes.
Now that I have learned to properly shift gears this is not a problem
The syncros are gone. They need to be replaced. It is a real bitch to get to the 3rd gear syncros and get them off.
If you do the job yourself you are going to need a press to get the 5th gear of the shaft so you can get to the 3rd gear syncros. Heat the gear or you may break it in the press as I did.
How am I so sure? Did it twice and did not replace the 3rd gear syncros the 1st time.
Here the problem, the syncros match the shaft speed and the sliders lock shaft to the gears via the syncros. (Call the dogs in a non syncro unit). The gears are in constant mesh but free wheel on the shaft until the syncros engage and lock them to the shaft. In order to lock them to the shaft they have to be spinning at the same speed. Where the syncro rides on the shaft it has a friction material like a brake lining which makes it want to stick to the shaft and spin at the same speed. When this material wears off, the syncros will not do their job and you can not down shift the unit no matter how hard you try. The shaft is at one speed, the syncros are at another and the gears are at a third speed which is slower because they are still being spun at the shaft speed for the higher gear that you are trying to come down from.
When you take it apart you will understand how it all works.
THe cause for the damage is due to not using proper heel and toe downshifting and using the trans as a brake. This burns off the friction material off the syncros. The syncros of the upshift see little wear because the trans is not being used as a brake and the syncros are not being used as break shoes.
Now that I have learned to properly shift gears this is not a problem
02-22-2006, 10:29 PM
#5
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Car: '85 TA
Engine: Carb'd 350, ported 416s
Transmission: retrofitted T5
Axle/Gears: 3.42 7.62" 10-bolt, locker
Originally posted by SDIF
The syncros are gone. They need to be replaced........Now that I have learned to properly shift gears this is not a problem
The syncros are gone. They need to be replaced........Now that I have learned to properly shift gears this is not a problem
agreed. needs new syncros.
SDIF: BTW, do you know if reverse is supposed to be synchronised on a T5? I took mine apart, and reverse didnt have one, but it didnt look like it was supposed to have 'em either. if this is the case, why did they do this?
02-23-2006, 08:08 AM
#6
Originally posted by SDIF
Try to swap out the transmission for a rebuilt one.
The syncros are gone. They need to be replaced. It is a real bitch to get to the 3rd gear syncros and get them off.
If you do the job yourself you are going to need a press to get the 5th gear of the shaft so you can get to the 3rd gear syncros. Heat the gear or you may break it in the press as I did.
How am I so sure? Did it twice and did not replace the 3rd gear syncros the 1st time.
Here the problem, the syncros match the shaft speed and the sliders lock shaft to the gears via the syncros. (Call the dogs in a non syncro unit). The gears are in constant mesh but free wheel on the shaft until the syncros engage and lock them to the shaft. In order to lock them to the shaft they have to be spinning at the same speed. Where the syncro rides on the shaft it has a friction material like a brake lining which makes it want to stick to the shaft and spin at the same speed. When this material wears off, the syncros will not do their job and you can not down shift the unit no matter how hard you try. The shaft is at one speed, the syncros are at another and the gears are at a third speed which is slower because they are still being spun at the shaft speed for the higher gear that you are trying to come down from.
When you take it apart you will understand how it all works.
THe cause for the damage is due to not using proper heel and toe downshifting and using the trans as a brake. This burns off the friction material off the syncros. The syncros of the upshift see little wear because the trans is not being used as a brake and the syncros are not being used as break shoes.
Now that I have learned to properly shift gears this is not a problem
Try to swap out the transmission for a rebuilt one.
The syncros are gone. They need to be replaced. It is a real bitch to get to the 3rd gear syncros and get them off.
If you do the job yourself you are going to need a press to get the 5th gear of the shaft so you can get to the 3rd gear syncros. Heat the gear or you may break it in the press as I did.
How am I so sure? Did it twice and did not replace the 3rd gear syncros the 1st time.
Here the problem, the syncros match the shaft speed and the sliders lock shaft to the gears via the syncros. (Call the dogs in a non syncro unit). The gears are in constant mesh but free wheel on the shaft until the syncros engage and lock them to the shaft. In order to lock them to the shaft they have to be spinning at the same speed. Where the syncro rides on the shaft it has a friction material like a brake lining which makes it want to stick to the shaft and spin at the same speed. When this material wears off, the syncros will not do their job and you can not down shift the unit no matter how hard you try. The shaft is at one speed, the syncros are at another and the gears are at a third speed which is slower because they are still being spun at the shaft speed for the higher gear that you are trying to come down from.
When you take it apart you will understand how it all works.
THe cause for the damage is due to not using proper heel and toe downshifting and using the trans as a brake. This burns off the friction material off the syncros. The syncros of the upshift see little wear because the trans is not being used as a brake and the syncros are not being used as break shoes.
Now that I have learned to properly shift gears this is not a problem
I think you broke yours because you have no idea and pressed off a gear that is only held in with a snap ring
remove that and 5th slides right off!no press needed for the 3rd gear syncro either! just a 2 jaw puller the toes on the legs of the puller need to be narrow but, that is it. if that is too hard o-well just clamp down since the blocker ring will be replaced anyway
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02-23-2006, 04:37 PM
#8
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Car: 85 camaro sport coupe
Engine: 2.8 MFI
Transmission: v6 700R4 wish it was a 5spd Stick
Axle/Gears: Stock non posi 3.42s
[Here the problem, the syncros match the shaft speed and the sliders lock shaft to the gears via the syncros. (Call the dogs in a non syncro unit). The gears are in constant mesh but free wheel on the shaft until the syncros engage and lock them to the shaft. In order to lock them to the shaft they have to be spinning at the same speed. Where the syncro rides on the shaft it has a friction material like a brake lining which makes it want to stick to the shaft and spin at the same speed. When this material wears off, the syncros will not do their job and you can not down shift the unit no matter how hard you try. The shaft is at one speed, the syncros are at another and the gears are at a third speed which is slower because they are still being spun at the shaft speed for the higher gear that you are trying to come down from.
When you take it apart you will understand how it all works.
THe cause for the damage is due to not using proper heel and toe downshifting and using the trans as a brake. This burns off the friction material off the syncros. The syncros of the upshift see little wear because the trans is not being used as a brake and the syncros are not being used as break shoes.]
so your sayin that there is no tooth / tooth connection beweeen the shaft and geers only a clutch like synchro? that is now how i understand the synchros to work all they do is bring the rest of the trans to the same speed as the gear you are shifting into and then it engages the dogs or whatever you want to call them and the load is on them not the synchro so using the trans to brake will not wear out the synchro. i have done engine braking on all the Manul cars i have had for years and have yet to have one goe bad of even start shifting hard. what kills synchros is not fully disengaging the clutch before you try to change gears.
When you take it apart you will understand how it all works.
THe cause for the damage is due to not using proper heel and toe downshifting and using the trans as a brake. This burns off the friction material off the syncros. The syncros of the upshift see little wear because the trans is not being used as a brake and the syncros are not being used as break shoes.]
so your sayin that there is no tooth / tooth connection beweeen the shaft and geers only a clutch like synchro? that is now how i understand the synchros to work all they do is bring the rest of the trans to the same speed as the gear you are shifting into and then it engages the dogs or whatever you want to call them and the load is on them not the synchro so using the trans to brake will not wear out the synchro. i have done engine braking on all the Manul cars i have had for years and have yet to have one goe bad of even start shifting hard. what kills synchros is not fully disengaging the clutch before you try to change gears.
02-23-2006, 11:13 PM
#9
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Car: 91 Z/28, 89 RS Race Car
Engine: 305 stock / ZZ4 AFR 195 9.7:1
Transmission: T5 / t10 / Jerico
Axle/Gears: 10blt w 3.42, 9 in w /3.80 DL
I think you broke yours because you have no idea and pressed off a gear that is only held in with a snap ring remove that and 5th slides right off!
Never said that I needed a press on 3rd gear.
Sounds like you have no Idea. I am only going from experience not somthing I read in Hot Rod or saw on my classic car where they work in a hospital environment. In the real word stuff happens.
I am trying to help. Do you agree that the syncro are shot? Or not?
02-24-2006, 06:16 PM
#10
No, the damn thing would not come off. I had to use a press. I had to take it to a transmission shop after removing the snap ring. I know the guy who owns the shop, went to school with his son 20 years ago, he said the same thing you did until he tried to get it off. The damn thing was stuck to the shaft. PERIOD. Were you there?
Never said that I needed a press on 3rd gear.
Sounds like you have no Idea. I am only going from experience not somthing I read in Hot Rod or saw on my classic car where they work in a hospital environment. In the real word stuff happens.
I am trying to help. Do you agree that the syncro are shot? Or not?
you are too funny guy! I have been through alot of these t5s not to mention many others t56- 700r4s and so on. unless you have the after market 5th gear (the pressed on style) then you may have had other issues on top of it.
now grinding. could be a number of things broken bearing under those gears (wc has them) broken key or out of place (happens) and yes worn blockers and if bad enough the slider and the gear.
now if you look I did give him some very helpful advice on using the puller.
now I don't read that hot rod junk.
I work on this stuff as part of my job (that is how I know!) so just because your shade tree prodject turned out like it did does not mean he will even have a problem. I don't care if you dated his daughter it really has nothing to do with how good of a trans guy he is. good luck and learn to chill out. with that temper it's no wonder the gear broke
Never said that I needed a press on 3rd gear.
Sounds like you have no Idea. I am only going from experience not somthing I read in Hot Rod or saw on my classic car where they work in a hospital environment. In the real word stuff happens.
I am trying to help. Do you agree that the syncro are shot? Or not?
you are too funny guy! I have been through alot of these t5s not to mention many others t56- 700r4s and so on. unless you have the after market 5th gear (the pressed on style) then you may have had other issues on top of it.
now grinding. could be a number of things broken bearing under those gears (wc has them) broken key or out of place (happens) and yes worn blockers and if bad enough the slider and the gear.
now if you look I did give him some very helpful advice on using the puller.
now I don't read that hot rod junk.
I work on this stuff as part of my job (that is how I know!) so just because your shade tree prodject turned out like it did does not mean he will even have a problem. I don't care if you dated his daughter it really has nothing to do with how good of a trans guy he is. good luck and learn to chill out. with that temper it's no wonder the gear broke
02-24-2006, 08:31 PM
#11
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Car: 1989 IROC-Z
Engine: 5.7L EFI LTR setup
Transmission: T-5 World Class
ANYhyoooooo w
Try letting the rpms fall to idle before you put it in the next gear . Might helps for a bit untill you get the tranny swapped /fixed.
Mine did that but I let it go and boom ALOT more stuff went wrong , Here is the end of the input shaft ( think thats it ) There was NO bearing
Synchros are shot . Get'r fixed
I ended up with busted gears , shafts , etc. I WAS bent on a numbers matching car , so I got raped on a price for fixing it . $2300 for parts/labour
Try letting the rpms fall to idle before you put it in the next gear . Might helps for a bit untill you get the tranny swapped /fixed.
Mine did that but I let it go and boom ALOT more stuff went wrong , Here is the end of the input shaft ( think thats it ) There was NO bearing
Synchros are shot . Get'r fixed
I ended up with busted gears , shafts , etc. I WAS bent on a numbers matching car , so I got raped on a price for fixing it . $2300 for parts/labour
02-26-2006, 06:53 PM
#12
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Car: 84Z28
Engine: 0.030 over 10.25:1 dart heads 350
Transmission: T 5 W.C. now
Axle/Gears: 3.73:1
5th gear is a press fit.....it "may" slide right off in some cases....syncrows are toast.......a rebuils kit is less that $150.....DO NOT HEAT ANY GEARS...they will fail....they are heat treated/tempered....... all you need is a good shop press and some basic hand tools........good luck!
02-27-2006, 05:46 PM
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Car: 91 Formula
Engine: L98 TPI
Transmission: 700R4
Axle/Gears: 3:42 posi
simple reduction of wear
I agree with all post on this one however a simple fix for once you get the trans together and back in the car.....
try to not rest your hand on the gear shifter as you drive around town, the pressure on the shifter adds wear to the syncros especially in 2nd and 4th gears....after rebuilding numerous t-5 for mustangs and third gens. the most common cause of wear to those syncros is pressure from the drivers hand(everyday driving not racing or quick shifting).... just a FYI thing..
Thanks
J
try to not rest your hand on the gear shifter as you drive around town, the pressure on the shifter adds wear to the syncros especially in 2nd and 4th gears....after rebuilding numerous t-5 for mustangs and third gens. the most common cause of wear to those syncros is pressure from the drivers hand(everyday driving not racing or quick shifting).... just a FYI thing..
Thanks
J
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