Bye Bye third gear!
Thread Starter
Joined: Oct 2002
Posts: 7,303
Likes: 1
From: West suburbs of Chi-town
Bye Bye third gear!
Finally lost third gear in my Z yesterday. So much for one more trip to the track this fall.
I was just pulling out of my neighborhood. Went through a bit of first at about 1/4 throttle or less, shifted to second more normal out of boost accel. Then shifted to third and added some more throttle and as soon as I got into boost at about 1/2 throttle my car vibrated massively and I instantly let off the gas. Went back in to second and it was fine...shifted to third and it's now a false neutral.
I know exactly what happened. I snapped the braising between the third gear engagement ring and the main gear. Very common failure on these transmissions. I knew of this possible problem a while back and last year had my transmission worked over and had a newly bought third gear shipped out to a company that could possibly beam weld it to eliminate the weakness. Well long story short, they lost the gear I sent and we had to put my trans back together without a stronger third setup. This result was inevitable.
Overall I'm impressed with how much abuse my third gear did take before it finally let go. Over 25K boosted miles all on drag radials with multiple trips to the track on slicks. Plus the failure point is engineered very well. When it fails it doesn't toss gear pieces all over the trans like some gear failures would. The car is totally driveable, it just doesn't have third gear.
I'll be looking into some other possible ways to solve this problem and I'll keep you all updated.
I was just pulling out of my neighborhood. Went through a bit of first at about 1/4 throttle or less, shifted to second more normal out of boost accel. Then shifted to third and added some more throttle and as soon as I got into boost at about 1/2 throttle my car vibrated massively and I instantly let off the gas. Went back in to second and it was fine...shifted to third and it's now a false neutral.
I know exactly what happened. I snapped the braising between the third gear engagement ring and the main gear. Very common failure on these transmissions. I knew of this possible problem a while back and last year had my transmission worked over and had a newly bought third gear shipped out to a company that could possibly beam weld it to eliminate the weakness. Well long story short, they lost the gear I sent and we had to put my trans back together without a stronger third setup. This result was inevitable.
Overall I'm impressed with how much abuse my third gear did take before it finally let go. Over 25K boosted miles all on drag radials with multiple trips to the track on slicks. Plus the failure point is engineered very well. When it fails it doesn't toss gear pieces all over the trans like some gear failures would. The car is totally driveable, it just doesn't have third gear.
I'll be looking into some other possible ways to solve this problem and I'll keep you all updated.
Registered User
Joined: Nov 2002
Posts: 1,038
Likes: 0
From: Winfield, IL
That's awesome that they covered it for you, but not an option for Brian unfortunately. This trans has a ton of other work done to it (by me and my boss) and I'll be fixing it for him.
I am currently exploring options to find a real remedy for the problem of 3rd gear breaking, rather than just throwing another time bomb in the trans and crossing our fingers. I was actually doing this last winter but the place that I sent a brand new 3rd gear out to lost the gear, and by the time that was made known to me, I had to get this trans back together so brian could drive his car. So I ended up just putting the stock 3rd gear back in it and crossing my fingers. Hopefully won't have to do that this time.
GTM was exploring straight cut gears. Not sure what happened to that... I remember someone posted pics of this exact failure - was it Scott (overzealous) or Todd (bzm)? They were also looking for a solution back then. Or was it you Brian? Was a while ago.
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Nobody runs one.
GTM ditched the straightcut gear set from what ive heard. They never really tested it because there didnt seem to be a need for it. Apparently now we also have a weak input shaft, as found out by SP. If my trans keeps breaking I am going to seriously look into a V160 (mkiv supra tt trans) swap.
GTM ditched the straightcut gear set from what ive heard. They never really tested it because there didnt seem to be a need for it. Apparently now we also have a weak input shaft, as found out by SP. If my trans keeps breaking I am going to seriously look into a V160 (mkiv supra tt trans) swap.
Registered User
Joined: Nov 2002
Posts: 1,038
Likes: 0
From: Winfield, IL
It was their rear diff that broke. Not the input shaft (which sucks because there is ready made solution if the input shaft had broken in a certain way).
Last edited by Nealoc187; Oct 23, 2008 at 11:35 AM.
Registered User
Joined: Nov 2002
Posts: 1,038
Likes: 0
From: Winfield, IL
Todd posted pictures of it if I recall. It was me and brian that were exploring a solution (todd may have been also, not sure) but when the part got lost that I sent out to have worked on, I put it on the back burner. Now it's back on the front burner.
Thread Starter
Joined: Oct 2002
Posts: 7,303
Likes: 1
From: West suburbs of Chi-town
I have been speaking with Sam at PAR about stronger gears. I will be getting them soon. Here is their contact information:
Ph: +612 9820 1100
Fax: +612 9820 1900
FYI, they are in Australia, so if calling, call very late U.S. time. If you want Sam's e-mail address, PM me.
Ph: +612 9820 1100
Fax: +612 9820 1900
FYI, they are in Australia, so if calling, call very late U.S. time. If you want Sam's e-mail address, PM me.
Nobody runs one.
GTM ditched the straightcut gear set from what ive heard. They never really tested it because there didnt seem to be a need for it. Apparently now we also have a weak input shaft, as found out by SP. If my trans keeps breaking I am going to seriously look into a V160 (mkiv supra tt trans) swap.
GTM ditched the straightcut gear set from what ive heard. They never really tested it because there didnt seem to be a need for it. Apparently now we also have a weak input shaft, as found out by SP. If my trans keeps breaking I am going to seriously look into a V160 (mkiv supra tt trans) swap.
thats funny bc I just told my friend when mine brakes Im going to do a th400
Thread Starter
Joined: Oct 2002
Posts: 7,303
Likes: 1
From: West suburbs of Chi-town
I have been speaking with Sam at PAR about stronger gears. I will be getting them soon. Here is their contact information:
Ph: +612 9820 1100
Fax: +612 9820 1900
FYI, they are in Australia, so if calling, call very late U.S. time. If you want Sam's e-mail address, PM me.
Ph: +612 9820 1100
Fax: +612 9820 1900
FYI, they are in Australia, so if calling, call very late U.S. time. If you want Sam's e-mail address, PM me.
Registered User
Joined: Jan 2009
Posts: 14
Likes: 0
From: ohio
I have no gears
I just got home from the MARINE an took my 03 track out. drove it for about an hour no problem. On the way home i turned my VDC off an got on it 1st 2nd no problem then 3rd. I had nothing all gears r gone. just a whole bunch off free play. will not engage any gear. Good thing i was close to home. Any idea what happen. THANKS ALOT for any help
what about the 370z gear do you think guys it would handle more abuse or not ?
also just throwing an idea spoke with GTM before maybe 8 months or so about converting to t56 and they told me its could be done but it wouldn't be easy ....
also just throwing an idea spoke with GTM before maybe 8 months or so about converting to t56 and they told me its could be done but it wouldn't be easy ....