Tranny Grenade FTGDMFL!
05-24-2008, 08:28 PM
#1
Tranny Grenade FTGDMFL!
So today a few friends and I pulled the tranny from my car. After sorting out some rather interesting issues with there the car sat, we got to work and got everything out. It looks like the output shaft bearing that is seated in the bell-housing literally blew up. You can see gears thru the bellhousing and what is left of the bearing.
I'm going to have to say this tranny is not rebuildable.
Excuse the ****ty pictures. I think my camera is dying.
S
I'm going to have to say this tranny is not rebuildable.
Excuse the ****ty pictures. I think my camera is dying.
S
05-25-2008, 05:46 AM
#8
Powershifting a high power engine on a weak FWD tranny with helical gears FTL.
because of the helical gears, there's a lateral force created when you're on the gas. too much lateral force- usually from slamming gears- and the mainshaft bearing will blow through the side of the tranny like this. seen it several times in the last few years.
because of the helical gears, there's a lateral force created when you're on the gas. too much lateral force- usually from slamming gears- and the mainshaft bearing will blow through the side of the tranny like this. seen it several times in the last few years.
05-25-2008, 06:18 AM
#9
Member
Join Date: Dec 2006
Location: OCEANVIEW
Posts: 115
interesting....soo is it better if modding the motor for higher HP i.e. turbo/SC to aslo have the tranny rebuilt/have the gears cryo'd as a precaution so this won't happen, or would this be more on the owner's do and don't list (if money is not an option). I know that back in the day when i was running my turbo b13, i didn't even think of upgrading the tranny or having to look at a tranny rebuild. this is interesting to know..I'll admit im not a tranny guru. IS it HP or Torque that would initially do that much damage, or the combination of both?
05-25-2008, 07:30 AM
#10
Having the gears cryo'd will help the gears survive but not the case. The lateral force is because of the way a helical gear is designed. The only way to help that is switch to straight cut gears.
http://forums.maxima.org/showthread....et+aftermarket
Good reading there.
http://forums.maxima.org/showthread....et+aftermarket
Good reading there.
05-25-2008, 08:10 AM
#11
Straight cut gears are MUCH stronger, but you'll have to put up with the "touring car whine!" with them. Not such a bad thing if it's not your DD, but if it is .... you'll get tired of hearing the whine after a while. Nice job though .... Buy another case, rebuild, call it a day.
I would guess it is more the tourque that will do this, and by tourque, I mean ... when you hit the clutch, it takes pressure away from the MS and IPS and they have a bit of slack room to move a bit. When you dump the clutch (shift at higher RPMs) you put a tremeandous amount of pressure / tourque on the shafts. When you load the gears nice and normall like, this should not happen. So ... my bigger question is .... how'd you do it? lol
I would guess it is more the tourque that will do this, and by tourque, I mean ... when you hit the clutch, it takes pressure away from the MS and IPS and they have a bit of slack room to move a bit. When you dump the clutch (shift at higher RPMs) you put a tremeandous amount of pressure / tourque on the shafts. When you load the gears nice and normall like, this should not happen. So ... my bigger question is .... how'd you do it? lol
that S/C will do it to ya!!! how much does a rebuild kit run usually???
05-25-2008, 12:15 PM
#16
Powershifting a high power engine on a weak FWD tranny with helical gears FTL.
because of the helical gears, there's a lateral force created when you're on the gas. too much lateral force- usually from slamming gears- and the mainshaft bearing will blow through the side of the tranny like this. seen it several times in the last few years.
because of the helical gears, there's a lateral force created when you're on the gas. too much lateral force- usually from slamming gears- and the mainshaft bearing will blow through the side of the tranny like this. seen it several times in the last few years.
Last edited by maximase86; 05-25-2008 at 12:17 PM.
05-25-2008, 12:21 PM
#17
05-26-2008, 05:32 AM
#19
Wow, I have never seen the mainshaft bearings fail. They're usually the least worn bearings in the tranny.
I have seen other parts of the tranny break loose and crack the case open when the parts get stuck somewhere else. Or if debris wedges the roller bearing, prevent it from rolling, and the bearing spins in the housing and then breaks it. The cross axle in the diff frequently fatigues and comes apart. I've seen a couple of housings busted open from that.
Dave
I have seen other parts of the tranny break loose and crack the case open when the parts get stuck somewhere else. Or if debris wedges the roller bearing, prevent it from rolling, and the bearing spins in the housing and then breaks it. The cross axle in the diff frequently fatigues and comes apart. I've seen a couple of housings busted open from that.
Dave
05-26-2008, 06:00 AM
#20
Junior Member
Join Date: Nov 2007
Posts: 31
if you've got a lot of power in a 4th gen engine, is this avoided by something like swapping in a 5.5 gen 6spd? i know not many people have done that (because of all the differences between the two), but since that tranny is from a heavier/more powerful car should it theoretically hold up better under hard driving?
05-26-2008, 11:02 AM
#21
What really needs to happen is for me to beef up the tranny itself. Moving the a 6-speed doesn't neccessarily solve anything. Plus to locate one, as well as all the cables, etc doesn't really make it worth it to me yet.
S
S
05-26-2008, 04:14 PM
#22
I agree ... you need a heavier duty trans for sure mate. I guess you could look into a racing trany, but I'm sure that'll set you back a LOT of money. Not to mention, it'd have straight cut gears and whine like crazy. lol
Does Nissan make a heavier duty trans case? If not ... can one be made? I am sure one could be modded / molded ... but again, it's money.
How much HP is the VQ putting out? And at what psi?
Does Nissan make a heavier duty trans case? If not ... can one be made? I am sure one could be modded / molded ... but again, it's money.
How much HP is the VQ putting out? And at what psi?
05-26-2008, 06:13 PM
#23
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Join Date: Oct 2005
Location: Middleboro/Carver, Ma
Posts: 4,572
Wow, that's crazy! Got any pics of the pressure plate? Are you SURE no clutch bolts came loose, I've seen similiar pics in the turd gen forum and that's what caused it, allthough in this it sure does look the mainshaft busted right through.
05-26-2008, 07:12 PM
#25
I think you need a tranny in better condition.
Get it rebuilt properly, put good synthetic gear oil in, and the proper clutch for your torque level. Make sure your suspension doesn't wheel hop and you'll have plenty of capacity. I'd say 300ft-lb with some measure of reliability.
The tranny housing doesn't bust out like that just from helical gear thrust. It takes another failure first to provide that kind of wedging action.
While the PPG and PAR gearsets are really nice products, for the price you can afford to frag a couple of rebuilt stockers.
Get it rebuilt properly, put good synthetic gear oil in, and the proper clutch for your torque level. Make sure your suspension doesn't wheel hop and you'll have plenty of capacity. I'd say 300ft-lb with some measure of reliability.
The tranny housing doesn't bust out like that just from helical gear thrust. It takes another failure first to provide that kind of wedging action.
While the PPG and PAR gearsets are really nice products, for the price you can afford to frag a couple of rebuilt stockers.
05-26-2008, 09:01 PM
#26
You didn't do that damage to that trans solely beause of torque. There are tons of maximas putting out WAYYY more torque than your car makes and that race all the time that have never had that failure.
It looks to me from the one closeup pic that the mainshaft bearing inner race is fragged. If that bearing was melting itself into oblivion, seized up or overheated the case in that region then that could have caused the failure.
I would bet any amount of money on that failure never occuring again to you. You don't need to worry about it. Just get a trans with gears that are in good condition, properly shimmed with good bearings, and you're good to go. If you want that piece of mind for your 3rd gear, consider a 6spd swap, aftermarket 3rd gear, or detailing and shot peening an OEM gearset.
It looks to me from the one closeup pic that the mainshaft bearing inner race is fragged. If that bearing was melting itself into oblivion, seized up or overheated the case in that region then that could have caused the failure.
I would bet any amount of money on that failure never occuring again to you. You don't need to worry about it. Just get a trans with gears that are in good condition, properly shimmed with good bearings, and you're good to go. If you want that piece of mind for your 3rd gear, consider a 6spd swap, aftermarket 3rd gear, or detailing and shot peening an OEM gearset.
05-26-2008, 09:02 PM
#27
I agree ... you need a heavier duty trans for sure mate. I guess you could look into a racing trany, but I'm sure that'll set you back a LOT of money. Not to mention, it'd have straight cut gears and whine like crazy. lol
Does Nissan make a heavier duty trans case? If not ... can one be made? I am sure one could be modded / molded ... but again, it's money.
How much HP is the VQ putting out? And at what psi?
Does Nissan make a heavier duty trans case? If not ... can one be made? I am sure one could be modded / molded ... but again, it's money.
How much HP is the VQ putting out? And at what psi?
05-26-2008, 09:05 PM
#28
S
05-26-2008, 09:13 PM
#30
I think you need a tranny in better condition.
Get it rebuilt properly, put good synthetic gear oil in, and the proper clutch for your torque level. Make sure your suspension doesn't wheel hop and you'll have plenty of capacity. I'd say 300ft-lb with some measure of reliability.
The tranny housing doesn't bust out like that just from helical gear thrust. It takes another failure first to provide that kind of wedging action.
While the PPG and PAR gearsets are really nice products, for the price you can afford to frag a couple of rebuilt stockers.
Get it rebuilt properly, put good synthetic gear oil in, and the proper clutch for your torque level. Make sure your suspension doesn't wheel hop and you'll have plenty of capacity. I'd say 300ft-lb with some measure of reliability.
The tranny housing doesn't bust out like that just from helical gear thrust. It takes another failure first to provide that kind of wedging action.
While the PPG and PAR gearsets are really nice products, for the price you can afford to frag a couple of rebuilt stockers.
S
05-27-2008, 10:04 AM
#33
05-30-2008, 10:23 PM
#35
I got the new tranny in today. I installed brand new seals, and throwout bearing. The left over oil that was in the tranny was really clean. The car is almost ready to go, but I do have a problem. I'm having a helluva time installing the driver axle. I've tested the new clutch and the pedal feel is nice and stock like. I can shift into every gear easily and smoothly.
S
S
05-31-2008, 02:47 AM
#36
Put heavy grease on the circlip. Center it as best you can in the groove of the stub. Slide in the stub until you feel the circlip touch, then draw it back out 3/4" and pop it in hard.
I would still have pulled the cover off the tranny to have a look at the diff bearings. It's 30min of effort now that's priceless later.
Dave
I would still have pulled the cover off the tranny to have a look at the diff bearings. It's 30min of effort now that's priceless later.
Dave
Last edited by dgeesaman; 05-31-2008 at 02:57 AM.
05-31-2008, 10:21 AM
#37
I got a view at the diff bearings when I was doing the seals. The cage and rollers looked really clean. Of course I couldn't see the entire diff, but I figure they looked alright.
S
S
06-01-2008, 12:25 AM
#38
I finally got the driver side axle in. However I got a pretty bad leak from the passenger side axle. After taking a look, there is a sort of metal ring that sits in the seal to keep the gear oil from coming out. However mine sticks out and wouldn't seat. After looking at it, it looks like mine was on backwards. So I reversed it, but it still sits pretty loose. It almost seems like the axle isn't all the way in, but it's completey against the carrier bracket and won't move further. I even went as far as to bringubg the axle to a local auto-supply. However the reman ones didn't have this ring. I would place my ring on the reman axle and it sits in about the same place.
The tranny is a VLSD tranny...but the old tranny was also VLSD, so I don't see there being any issues with the axle not fitting.
Thoughts? I'm am so close, all I need is to put this axle back in, fill the tranny, and I'm completely done.
S
The tranny is a VLSD tranny...but the old tranny was also VLSD, so I don't see there being any issues with the axle not fitting.
Thoughts? I'm am so close, all I need is to put this axle back in, fill the tranny, and I'm completely done.
S
06-01-2008, 09:10 AM
#39
But, you couldn't see the races to see if they were pitted or the rollers were pitted.
Dave is right IMO - priceless information when you have to tear it down in 5 or 10 k miles. But ... glad you got a VLSD, should be nice!
