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t56 sounds like a grinder in 5th and 6th..


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man...after so many hours and work put into this piece of $hit tranny, i cant believe the 5th and 6th grinds before it goes into gear. i can hear the teeths touch and i dont even know if its going to engage or not. the previouse owner of the t56 told me it would go into gear (5th-6th) but wont go catch. it just whistles..damn...i bought new gears, steel shift fork, new blocker rings and syncros for this thing and spent 100s of hours of work and labor into rebuilding this thing and now it looks like its not going to work. after rebuilding the trans, it seems like its no different from when i recieved it from the previo0use owner. the car is still on jackstands and i tested the gears real quick with the tranny dry. 1-4th works perfect real smooth. 5th-6th and reverse has the grind. i rebuild it myself and when i opened it, the 5-6th gear looks perfect, thers no sign of grinding or anything, test shifted with the end case open and the fork shifted the gears into place but dont know whats up. this thing is getting me frustrated, i feel like im about to give up on the z. i might just blow the crap out of the trans and buy a new one or put it up for sale for anyone who might be interested and fixing this little problem. i know its something little but i give up on this tranny rebuild...it has so many brand new goodies inside of it too. anyone have any inputs on this??? i might just drive this on 1-4 daily...its sad...

 

t56_top_view.JPG

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I know how you feel. It probably will not be the last time you get so frustrated with the car...

Let it sit, work on something else, maybe take it to a transmission shop and some input?

I bought a used 95 motor and T56, have had it for 4 years and not yet tried 5th and 6th, so cross your fingers I could have the same problem.

 

One good note, you now know a lot about this transmission, you WILL get it figured out.. and if you ever have another trans problem you will probably solve it quickly...

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[sNIP]5th and 6th grinds before it goes into gear. i can hear the teeths touch and i dont even know if its going to engage or not.

[sNIP]..damn...i bought new gears, steel shift fork, new blocker rings and syncros for this thing

[sNIP] after rebuilding the trans, it seems like its no different from when i recieved it from the previo0use owner. the car is still on jackstands and i tested the gears real quick with the tranny dry. 1-4th works perfect real smooth. 5th-6th and reverse has the grind. i rebuild it myself and when i opened it, the 5-6th gear looks perfect, thers no sign of grinding or anything, test shifted with the end case open and the fork shifted the gears into place but dont know whats up. [whack]

 

 

Sounds like you have replaced all the offending parts, which leaves possible assembly problems and clearances. The expensive stuff is hopefully taken care of, only frustration left to deal with (some time and a couple beers often helps me with that).

 

I'll assume that you bought a small parts package and changed out any needle bearings involved. Since the trans uses tapered roller bearings, is there a procedure for centering/ setting end play?

 

I did a few minutes web cruising on T56's, and there is a lot of stuff out there, including this article..

http://www.chevyhiperformance.com/techarticles/148_0405_tough_t56_transmission/photo_04.html

 

This forum..

http://www.ls1tech.com/forums/archive/index.php/t-2774.html

 

Which includes this recommendation:

For future info here is the # to Westech ask for Norm he is really nice. They can blueprint your tranny and put in strengthend parts/synchs.

262-889-4346 ask for Norm

 

 

 

Could it be that what you are feeling is normal? As things come together, there is a moment of first contact; If a person feathers from gear to gear, there would be little pressure on the synchro rings to bring the gears to speed. (Also, I don't know what you mean by 'dry'. Dry will not act like lubricated).

 

As to the PO's complaint of it falling out of gear- that problem should be gone with the new parts. The article referenced above shows a Viper gear with longer dogs to alleviate a breakage problem. Note how short the dogs are on the stock gear. Lots of shifting tends to wear the sides of these into a ramp, at which time the trans pops out of gear.

 

Wish you luck.

 

 

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If you are testing it bone dry, the syncros definately will not work. They use the viscosity of the oil to create friction. I know that in my old VW gearboxes, you could tell if there was a problem because 5th would start to grind. 5th was positioned at a point in the gearbox that would run dry first if oil level was low. Try some good quality GL-4 oil. GL-4 isn't as slipperly, and while bearings may not last quite as long as GL-5 oil, they generally shift much better with GL-4, like Redline MT-90.

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unfortanantly, i tested it bone dry(no more then 30 seconds). im sure its not going to work since the grind sounds like the 5-6th gear drive is just spinning around the main shaft. i pulled the 5-6th gear drive with the gear puller when i took it off and when i went back to install it, i think i didnt press it down enough to get a good solid grip around the teeth on the main shaft to lock it in tight. it might of slipped out but who knows.

 

the t56 is a pretty hard trans to understand and when you open it up and take everything out, it looks like hell. i might just use the 1-4 gears and avoid the 5-6th gears. i dont even know if reverse works. the previouse owner says all the gears worked except 5-6th. they share the same gear cluster.

 

as of right now, the 5-6th goes into gears but makes that grinder noise like a blender blending some ice or something. ill just let it be for now and see what happens when i drop it off the jacks and put in the driveshaft.

i tested it dry with no drive shaft and on jack stands for a quick test. 1-4 has hardly no machanical sound to it but the others annoys me just hearing it disapoints me.

 

the money and time alone, spent on rebuilding this tranny, i could of bought a decent used one already but i thought i might of wanted a tougher trans and so i bought the rebuild kit with all new syncros and rings and also got a 3-4 steel shift fork and 1-2 and 3-4 new gears and new syncronizers. must of been over 500-600 just in parts alone. feels like a waist of parts, labor, time and money.

 

love-my-v8-280z.--..are you saying you had the trans for 4 years and never used 5-6th gears? im using the car for city use, you guys think i can get away with no 5-6th for now? whats the top speed for 4th anyways? 70mph?

 

agolphart--you ask..

I'll assume that you bought a small parts package and changed out any needle bearings involved. Since the trans uses tapered roller bearings, is there a procedure for centering/ setting end play?

 

according to the manual, its not neccesary to set the endplay if you dont replace the bearings. i didnt replace the bearings on this one since it still looks good. i wouldnt want to mess with the bearing in the first place because setting end play and removing and installing the bearings is a PITA.

 

Could it be that what you are feeling is normal?

for sure the feeling is not normal. 1-4 didnt make any noise, it wouldnt make any since for 5-6th to make that noise. i could be wrong and i wish it is normal.

 

thanks for all the replies and wish me luck.

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The 5/6 shaft end may be shot. To add to the problem the 1-4 countershaft may also be toast, since they interlock.

 

The main shaft holds 1-3 gears and synchros and in the tail, it holds the 5/6 countershaft. (remember 4th is also your output shaft) The 1-4 countershaft (driven gear as it's called in the manuals) has a splined opening that the 5/6 gear shaft locks into. If that spline is damaged, it will act just as you describe. If that is the problem, you are looking at major $$$ for a repair. I think the 1-4 countershaft is like 1100.00.

I actually have a spare 5-6 shaft and 5-6 countershaft.

Reverse is on the main shaft, so if your problem is the 5-6 shaft end, reverse will probably still work.

 

By the way, I think I can get 130mph in 4th.

 

Good luck, and I hope this is not what you find.

 

5-6-shaft.jpg

 

Jody

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unfortanantly, i tested it bone dry(no more then 30 seconds). im sure its not going to work since the grind sounds like the 5-6th gear drive is just spinning around the main shaft. i pulled the 5-6th gear drive with the gear puller when i took it off and when i went back to install it, i think i didnt press it down enough to get a good solid grip around the teeth on the main shaft to lock it in tight. it might of slipped out but who knows. [snip}...

 

Could it be that what you are feeling is normal?

for sure the feeling is not normal. 1-4 didnt make any noise, it wouldnt make any since for 5-6th to make that noise. i could be wrong and i wish it is normal.

 

thanks for all the replies and wish me luck.

 

Yup, not normal. My interpretation of what you were saying was that it only made noise as you were shifting it. I'm afraid JBC3 has the right of it.

 

 

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:nono: don't give up on the Z. Take a few days away from working on it and regather your senses. You'll be happy you did.

 

Yea I have a noise in my T56. Repair bills $ blah blah blah. It's driving me nuts! I am not giving up either.

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Who's to say the clearances were normal in the first place since it did the same before you started replacing parts?..............

 

In all my years of exp, there's only one way to do it, PITA or not, and that's the complete, leave no stone unturned, check everything way.

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Most mechanical things built on the same design tend to fail in similar patterns (develop common/generic problems).

 

Odds are good that if you call the guy mentioned in my first post, he would be able to tell you exactly what's up.:icon14:

 

Personal opinion: Things mechanical should not be run dry... I put everything back together lubed.

 

 

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when i bought the tranny and took off the rear cover, there was no signs of damage anywhere but some worn blocker rings and that was it. the magnets had very little deposits which looks normal compare top other t56 magnets ive seen in forums. i dont think the counter shaft is toated since it wasperfect when in pulled it in the first place, when i installed it, i pour fluid onto the gears itself but that doesnt mean anything, and i also lubed everything including the gear teeths with moly lube.

 

i remember clearly when in installed the 5-6 gear cluster, it had a little play in it and seems like it wasnt pressed in deep engough. would that cause this problem.

8f_1_b.JPG

 

jbc3, i know what you mean by the spline openning where the 1-4 locks into the 5-6 shaft. when it happened from the previouse owner, its the same thing happening as what i discribed, i expected the same thing but when i took it appart, the lock teeth on the end shafts looks normal. no chip or anything.

 

well, the engine is in and eveything is all wired up nice and neat, let me get this thing on the road and drive on the 1-4 for the moment just to make me happy! i hate pulling the trans while the enigne is still in, since its all in nice and neat already, ill just use it for the measurments for the driveshaft and tranny mount and get this thing on the road and see what happens.

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The 5-6 countershaft is splined the entire length. You can see the splines in your picture. There is no way to install this wrong. You can not get the snap rings on if it is not on far enough. Besides, the mainshaft is also splined the entire length where the countershaft goes... Newer transmissions (ones with less than 10K on them you usually have to use a puller to get it off. Older transmissions, it will slip right off. If the main shaft is shot or the teeth on the 5-6 countershaft are shot, the same thing could happen also, but I think you would notice. If the teeth in the countershaft broke off cleanly, they would not fall out into the transmission. They would ride in between the 2 shafts and fall out when you pulled it apart. (unless the PO is not fully disclosing what he found when he pulled it apart)

Personally, I'd pull it out and pull the tailshaft off and run it through it's paces with something on each end where you could put some torque on it so you can see the problem. DS yoke on one end and a old clutch disk on the other end. It will be obvious.

 

Jody

 

Here is a picture of a real magnet mess !!!!

 

magnet%20mess2.JPG

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your picture for sure is definantly not what i saw when i pulled the trans! wow, thats real grinder there...

 

believe it or not, my 5-6th gear cluster does sit pretty loose. i thought the same thing when i installed it, theres not enough room to press it in, not enough teeth like i said on the main shaft to get a good press in lock. the rings actually did go on so i left it the way it was thinking thers only one way to install this!

 

my magnets did not look nothing like the pic. it has little and very minimal deposits on it only. you can say, metal dust!

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Here are a few more trashed tranny pics for your viewing pleasure. The crushed tranny came out of a friend's car. The 3 shift detent clips broke out of the 3/4 syncro and the tranny went into 4th and 1st at the same time. 1st won :-) . 396 stroker LT1 with a D1 supercharger, 611 RWHP. By the way, those 3 detent clips are like $2.00 each. It can be the smallest thing that can cause alot of devistation.

In the last picture you can see the splines where the 5-6 main shaft have to lock into, in the top of the 1-4 countershaft.

 

4th%20main%20and%20counter%20shaft%202.JPG

 

4th%20counter%20sharft3.JPG

 

overall%201.JPG

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man, thats some nasty pics, but unfortantly, i think the tranny is up for grabs! it has alot of new parts in it. im not sure how it can happen but i filled it up with fluid tonight and tested it again. i dont even have to use the clutch and it goes into 1 through 6 and reverse. the 5-6th still makes the grinding noise but stop shortly after it is in gear. this is wierd. im not sure whats going on anymore. i mean, i can just shift and it will go in gear without even stepping on the clutch. what the heck is going on here.

 

im using a tilton 7/8 master cylinder and a f1 stage1 clutch with new throwout bearing and everything. this is crazy. i dont get it. i better see metals all over when i pull it appart cause then if i see nothing, this tranny is curst. i even test shifted it with the case off before putting it all back together and the syncros seems to slide from 1st to second perfect and the 3rd to 4th perfect and even 5th to 6th...the syncros locks it all in when i tested it but whats up with not stepping on the clutch? i know i got a bigger problem but not sure how this can be. i spent 3 months building this tranny making sure everything was in place and even tested it like 100 times before putting on the tranny case. i guess building tranny isnt my thing....damn it....this sucks..knowing i have all the new parts in it and not work. what can cause it to go into gear without even stepping on the clutch?

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You see those tapered roller bearings those are like pinion bearings, those have adjustable clearances, if those aren't right the entire trans won't function properly. I'm not T56 expert by any stretch of the imagination but my guess is If you check shaft endplay you'll find the whole trans is in need of a proper rebuild. If you'll set your mind to getting that done you'll be all smiles in the end! :D

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i know about the bearing clearance. the manuals say its not neccesary to clearcance the bearings as long as they are not removed. im not sure if its true or not but what their trying to say kinda makes sense since its in its original pressed dept, its not neccesary to clearance it since it was never removed or moved out of the original spec. does that make sense??? hard to explain.

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