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Hi everybody, I have a 1970 nova with a 1988 Camaro t5 transmission. I am experiencing a metal on metal grinding sound on deceleration/engine braking. The sound is most noticeable in first and second, existent 3rd and i cant hear it in 4th. It goes away with the clutch.
I've posted on stevesnovasite, but i figure this is a good resource to ask aswell.
If anyone has any incite in what it could be that would be really helpful. I didn't do the conversion so i don't know what pitfalls there could be related with it.
I'd do a careful listen of the rear diff. and trans. to pinpoint the location and pull the trans. accordingly.
The countershaft bore in the front of the case is known to open up with wear and may leak. A basically fine V8 1988 T5 might warrant a G-force case and rebuild kit.
Sorry to dig this thread up, I work on the car in short stints and it's been a while. I will pull the trans next and inspect it as well as change to an s10 tail and shifter.
I forgot to mention that the transmission shifts smoothly except that it has a consistent grind going into 4th gear. A little research has told me that this might be an alinement issue or pilot bearing/bushing? (See: https://www.thirdgen.org/forums/tran...oing-into.html) Is this something that could have been messed up in the conversion?
You could check belkhousing run-out, make sure the pilot end of the maindrive is good, the pilot bushing in the crank is good. Make sure your bellhousing opening matches the bearing retainer ring and isn't a big truck bell opening.
I realize fhe oldcar owners have a hardon for original shifter position. With the T5, going to an S10 shifter position lengthens the shifter, hurts ergonomics. Instead, update the console, run the right bellhousing, and enjoy the shorter shifts.
All good suggestions, ill do my homework and post what i learn.
Checking my thought process: If it were something related to the pilot bearing it makes sense that it would be louder in the gears with the ratios furthest from 1:1 right? This means i should hear it in 5th? Id wager something is wrong with the bellhousing because i think some of the parts there are pretty bodged together, that and the janky adapted mechanical clutch linkage.
As for the shifter, the reason i'm switching is that i have bench seats and i cant reach the pedals well before the seat hits the shifter. If i had buckets i'd agree with you. The benches i have are in good shape and i think they are a neat aspect of the old car.
It is unfortunate because the tailhousing i have is an electronic speedo and ill lose my stock mechanical speedometer, so i do have some incentive to keep the camaro parts. I figure id like to try the alternate shifter location and if a nice set bucket seats come my way ill have the camaro parts to change back.
There is a pilot bearing inside the input shaft. The main shaft runs in this bearing and that is all that supports the main shaft in the front. It's very common for this bearing to go bad in the T5. When this happens it lets the main shaft and the counter gear separate and the gears don't mesh as they should. When you are in 4th gear the main shaft and input shaft are linked directly, so this is not an issue in 4th. However it does make it harder to get the transmission into 4th because the shafts are not lined up correctly for the synchronizer to work properly.
If you run a S10 tail housing on a Camaro transmission you will not be able to use the speedometer because the location of the drive gear on the main shaft will not line up with the hole location on the S10 tail housing. You would have to use the S10 main shaft to make it work. If it turns out that you have the problem that I described above then you will have to replace the main shaft and the input shaft to fix it anyway.
Sorry to dig this up from the grave but i only get to work on the car for holidays.
So i managed to pull the transmission and found what appeared to be foreign material on the input shaft, probably from the pilot bearing. It also looks like the tip of the input shaft may have been rubbing on the crank. I am going to pull the clutch and see if i can dial out the runout of the bell housing next.
Ill also be swapping the tail housing. While i have the lid off are there any tell tale ware points i should be looking for in my t5?
Like i said before it shifts okay except for 4th, the only reason i am pulling it is the grinding sound while driving at constant speed. This is a 14 spline wc t5 unit. Is there any difference in capability of the 14 spline vs the 26 spline wc t5's
Would you recommend grinding down the input shaft? if it is interfering it is just by a hair... I don't know how these cranks/pilot bushings usually look taken apart.
I have a bit of a scraping clutch sound to boot, and now that i know that it is a v6 t5 that might explain it, sounds like the clutch i have is either wrong... or a frankenclutch.... That said it does engage and disengage smoothly and works just fine.
Grinding . . . Assuming you' have a V6 T5 and the Nova has a SBC, I don't know if the pilot end of the main drive is longer and interfering; some of the V6 units were. If you're talking about repairing the outer surface being damaged, yes repair it; perhaps with a hardened sleeve pressed onto a reduced Dia. , then honed down.
The roller pilot bearings are a bit notorious and have been in service by GM since the early 90s. If you look up pics of a new one, you may see the bevel, a seal inside that, and roller bearings inside that. Yours looks dirty inside; normally they should be lightly greased. And it doesn't look like rollers are present, maybe.
Happy wrenching and holidays.
I just indicated the bellhousing. I got the needle to move a total of 0 to -.007. Is this within spec, correct? Ill tear apart the trans tomorrow to put check the input bearings and swap the tail housings. I think i will be able to scrape the extra material off the input shaft, i was just concerned about the input shaft length.
The pilot in the crank is a bushing and the engine is a 2 piece rear main engine. The clutch is hilariously small, and probably mismatched.
Finally got to tearing down the trans.... Looks like the pilot rollers are pretty chewed, so 100 internet points to all that guessed it!
I noticed the reverse looks pretty chewed, and there is a chunk taken out of the end of third. Other than that and some debris at the bottom everything looks ok. Here are some pics incase you guys can see something i cant. i haven't had a manual trans apart before so again, i am not sure what to look for other than the obvious.
I'm not sure a v6 trans is worth a whole rebuild, but if i can throw a new bearing in and get a bit more out of it i'm in. Does anyone know where i can source new pilot needle bearings quickly? Also other than runout on the bellhousing what would cause this to happen?
That's what I figured. The shaft needs to be replaced. Does the inside of the input shaft look like that too? If it does then that needs to be replaced too. There are places that recondition the shaft. I've done it myself. They weld the shaft and then regrind it. You can buy a reconditioned shaft at a transmission shop or some auto parts stores. I usually get my T5 parts from Rockland Standard Gear.
It is good for parts. I've used many transmissions like that to fix other transmissions. If the counter gear is good then that's worth something and the other gears are worth something. There have been times that I needed a good case, so that is also worth something.
I'm going to assume that the input shaft was interfering with the crank... From the t5 info page
Originally Posted by 92RS_Ttop
Since I'm actually running the V6 T5 behind a 350, I'll add my .
The clutch disc that Pat Hall and Big Gear Head are referring to is from an 82 GMC S15 with a 2.8L V6. Part # at Autozone is CP4201, it has the 14 splines and is listed at 9 11/16" diameter.
Centerforce used to make a 10.5" 14 spline clutch disc for S10 V8 conversions but Summit apparently doesn't carry it anymore.
You could also try a disc from an Chevy Astro Van with the 4.3L V6, but it's an 11" clutch so I'm not sure it will fit inside the pressure plate.
As for transmission modifications, you need to cut about 1/4" off the front of the input shaft. I also used my angle grinder to chamfer the leading edge of the input shaft like it was originally. That is the only change I had to make to the transmission to get it to bolt up.
First gear is very short as was mentioned, I find myself shifting almost immediately into 2nd with 3.42 rear gears.
On a side not how much work would it be to go from a t5 to a tko? How much does a 3rd gen t5 have in common with a tko?
It seems my bellhousing(with adapter plate), crossmember and clutch linkage would carry?
Would i need a shorter drive shaft?
(yes i realize i am asking a 3rd gen f body forum about a 3rd gen nova.... but you guys have been awesome)
There is a fair amount of reading about the TKO here. Use of an adapter plate, and without are mentioned. I think there is at least one TKO setup that allows a yoke-change only driveline re-use. The bell adapter plate with a window right in front of the countshaft bearing is to be avoided. I am a big fan of getting ratios of the rear and the trans. just right so the car is fun to drive. At this point, an aftermarket gear set to make a V8 T5 is one way to go, and the T56 and TR6060 are, too. Power level and current rear gear might help decisions.
09-05-2016, 02:18 PM
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