strange rattle from trans area when clutch is out

[97grnrs]

i hear a rattle/bearing noise from the pass trans area, i replaced the throw out bearing last night it still does it. it sounds almost like the same noise when a throw out bearing goes bad, at idle i dont hear it . the engine rpm has to be like 3k or higher to hear it at idle. but if i push clutch in it stops, when im driving i can slightly hear it mosly only on decel. when i accel its quieter, so besides the TOB what could poss make that similar noise and go away when the clutch is pressed in? 95 awd talon tsi

 

[97grnrs]

just gave dealer the part numbers. 30$ for synchro and spring. i ordered both. should be in wed. ill be switching back to synchromesh once i do this also , i like the shifting in cold weather better with it compared to lucas 75-90 synt.

 

[hotrodssnova]

Twicks69 sells part on here also. Just got a bunch of shims from him 2 weeks ago. Look in the supporting vendors in the market place at the top of the page.

 

[Boostdriven]

John Shepard told me to use 2 qts of shockproof light weight and 1 qt of mt-90, total of 3 qts.

 

[97grnrs]

nobody sells the shockproof around here. i had synchromesh in it before and it felt nice and smooth. ive been searching for any negative effects of using synchromesh and havent found any yet so i guess ill try that again. it only holds 2.4q , 3 would be too much. ive used synchromesh in alot of my turbo hondas and a subaru and had good luck. hopefully dsm trans will not have any problems using it also.

 

[Boostdriven]

I know 3 qts is a bit more then what factory calls for but that's what John Shepard told me and it made sense. It's not going to hurt anything but it will keep the gears more submerged in oil.

 

[97grnrs]

it also will leak out of the axle seals and anywhere else if its over pressurized

 

[Boostdriven]

If your axle seals are bad they will leak with 1 qt in there, I've been running 3 qts in my tranny for years without a single drop leaking out. My friend I just told you what the problem with your tranny was without looking at it, you think I would mislead you on something as simple as how much oil to put in it oh and there is no oil pressure in your tranny and the pressure that is generated by heat should vent out the breather on top of the tranny.

 

[97grnrs]

i know its not pressurized like oil in the motor is but it still builds up pressure from moving parts.. oh well i just wanna get this whole thing done and pray nothing else goes wrong for a long while. i dont know if the new synchro and wave spring will stop it from rattling but at least its a try. if not ill just have to live with the rattle.

 

[Boostdriven]

If that rattling continues PM me and I'll give you my number, it might be a bit easier to figure it out over the phone. Good luck with it though.

 

[acidreian]

I know this sounds funny but i had the same problem and it was because i was missing the last bolt on te Tran the noise freaked me out for about a week I had to Drill out the backside of the block to allow a larger bolt above the T-case threw the block into the transmission. with that being done my transmission and clutch are silent.

so before you tear apart your transmission if you already havent think if you have all 4 bolts and there torc'd down wit locktight

 

[Archer Fabrications]

John Shepard told me to use 2 qts of shockproof light weight and 1 qt of mt-90, total of 3 qts.

But 100% mt90 in cold applications.

2qt ltwt shock proof 1 qt mt90 for 600hp

If it's too notchy do 1qt light weight 2 qt my90.

Also i don't think you can fit all 3 qts in without oozing out the breather hole. Just pump as much as you can until it starts to ooze out pump a few more times ten plug the trans.

This happened with my t case .

Shep also said you can fill it from the reverse switch hole.

 

[97grnrs]

well i know for sure the noise is that synchro rattling around. im just not sure if the new one and new spring will cure it. i hear it wont but they dont come from the factory rattling like that so there has to be a fix for the rattling synchro

 

[97grnrs]

well the new synchro and wav spring didnt fix it. i guess its doomed to rattle forever, i am thinkin about bending the wave spring a little more so it presses on it harder and maybe will help quiet it down. i dont know. its really annoying.

 

[Archer Fabrications]

Dude could it be the tcase or rear diff?

 

[97grnrs]

nope its 100% that synchro. the only thing that holds pressure on it is that dumb wave spring which barely holds it in place. if i set the synchro on the case end and wiggle it side to side i hear the exact noise it makes when im driving and things are vibrating.

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this is the source of the rattle.. note the small gap between the inside of synchro and part it sits on. its rattling around when car vibrates

 

[Archer Fabrications]

How can you be positive if you replaced it new? That it is still that synchro.

 

[97grnrs]

i know it is for sure. i can put my hand on the case directly where that sits and have someone hold the idle around 3k and i feel it rattle right where my hand is. its like its not tight enough in there to hold pressure on it so it wont rattle.

 

[Archer Fabrications]

Maybe a clip of some sort is broken, sounds like deal with it or get a nee trans if replacing it did nothing.

 

[97grnrs]

the only thing i found on google about this was someone had the same problem and found out the trans was shimmed improperly when rebuilt causing the same problem im having. id like to find a spare trans anyway but in my area thats hard to come by. or even a trans rebuild kit with all the synchros and stuff in case i ever decide to tear into it. another thing i notice in every diagram i find it show the wave spring and the rev cone but i never see a pic of the synchro , is this synchro supposed to be held onto the gear assembly somehow? cause on mine i can just lift it right off then stick it back on nothing locks it into place?

 

[Boostdriven]

There is nothing that holds that synchro in place besides that wavy ring. Synchro just sits inside the 5th/reverse hub/sleeve assembly. What tranny oil are you using? When you had that cover off did you try to move the gears to see if there was any play in the bearings? Did you do the test I told you to do before, while driving about 20-25 mph in 3rd gear press the clutch in but leave the car in gear, shut off the engine and listen for that noise.

Another thing I asked you before was do you hear that noise go away when you press the clutch in all the way to the floor (releasing the clutch completely) or does it go away when you barely press on the clutch like 15%-20%

 

[97grnrs]

ive tried a few diff trans fluids. seems the same no matter what. currently im running 1q 75w90 gear oila and 1.4q of synchromesh. when i let the car idle around 3grand to make it rattle i can press the clutch in about 40% and the rattle stops. i think thats because its taking away the vibration from the drivetrain and stopping the loose fitting synchro. i will try the cruise test later but i think it will stop rattling soon as engine shuts off due to no more vibration. i do have solid mounts and solid rear diff bushings so i know im gonna hear things rattle but ive never seen a case where a synchro fits loosely enough to rattle in the trans.there was also no play in the gears or even the input shaft when i had trans off. if i spin the input shaft its quiet also it only happens with vibration at certain frequencies , like when the car is under load and im on the gas the noise stops because its not causing a major vibration but soon as i let off the gas it sounds like marbles in a can type noise. the fluid is perfectly clean. no shavings at all so i really think its jus this synchro rattling around. i can even put my hand on the case where it sits and feel the vibration from it, i just tried the driving test. i still hear rattle when i shut engine off while coasting also

 

[Boostdriven]

Bottom line that noise wasn't there from the factory so something is causing that. I didn't think about this before but you could have done a little test when you had the cover off. You should have taken that synchro and the wavy ring out and put the cover back on. You wouldn't even need to use silicon on it for the test, just make sure it was tight. Dump your oil back in it and then see if it still makes that noise. If the noise is gone then you know for sure that its that synchro but if the noise is still there then its something else. I know its going to take some work but it might be worth a try.

Few questions, when did the car start making that noise, did you buy it like that or did it happen after you bought it or did you change your oil and then it started to do that?

If it all turns out that indeed its that synchro making the noise then what I would do is drain that oil that you have in it now. Go get 3 qts of some good 75-90 and run it. That thin stuff you got in there now is not helping you. If your car was making like 500 HP then you might need to use something else but for now I would run whatever it came with from the factory. If your seals are not leaking now then that extra 0.6 qts is not going to cause any issues, I promise you that. Since the oil level will be a little bit higher it will be easier for oil to get to that synchro and the thicker oil should help quiet it down.

I've seen those cars with over 180k miles all stock and the trannys worked fine. Anybody who drive their turbo awd eclipse/talon 180k miles and leave it all stock, probably had their oil changed at a shop in which case 75-90 would be put back in it. My point is that if all stock car can go that many miles on 75-90 then what's the point of trying to use something else. If your making a lot of power then its a different story.

 

[WES_393]

^ I agree. It would be best to just run the factory spec 75-90. Or DiaQueen if you can afford it.

It's also highly suggested that you avoid Syncroshift or Synchromesh products. For more info check out this link: Oil – Jacks Transmissions LLC

 

[Archer Fabrications]

Jack also said light weight shock proof ruins the synchros, shep disagrees though.

 

[97grnrs]

I was going to take out the synchro and try it but I wasn't sure if anything would happen from running it without that synchro maybe the pins with pop out or something. its always made the noise since I got the car changing fluid hasn't made it louder or quieter. when I took the case off there was signs that the trans was apart before. If it wont hurt anything for sure ill remove the synchro and wave spring today and run it on the lift and see if it still rattles. but i dont wanna do it unless im sure the pins or something wont pop out from running it like that, ive heard soo many diff opinions on synchromesh so i dont know. It does shift smoother with it , my 3rd and 4th gear feel a bit notchy sometimes so thats why i like to run it but i dont know.