2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

Drivetrain not holding up

Thread Tools
 
Search this Thread
 
Old 08-16-04, 01:34 AM
  #1  
Lets rock.

Thread Starter
 
flamin-roids's Avatar
 
Join Date: Apr 2004
Location: SLC, Utah
Posts: 1,355
Likes: 0
Received 0 Likes on 0 Posts
Drivetrain not holding up

My much anticipated 5 speed swap has began to show its ugly side. The trans I installed was a TII trans with 151k miles and I still have my 3.90 rear diff. My problem is I can't unleash this car because the syncro on 2nd is shot and the 3.90 just sucks off the line. Granny shifting combined with the 3.90 and closed 5th and 6th ports (fixed that) and tires that I swear was coated in crisco I slugged it through the 1/4 in 18 flat (at 4700ft of course). The motor is plenty powerful with a new light flywheel and new TII clutch. I'm going to rebuild this trans so what should I replace to ensure smooth 8k rpm+ shifting and also I need custom bushings for the crossmember because I had to use the auto crossmember and the bushings didn't exactly fit so there aren't any bushings. I'm using royal purple gear oil and the trans holds all gears just fine. 2nd gear syncro is definitly gone and it shudders at 7k+ shifts. A 4.30 rear is in the works and new Toyo's are on the way. Just need advice on rebuilding this trans and with what parts.
Old 08-16-04, 09:03 AM
  #2  
Displacement > Boost

 
88IntegraLS's Avatar
 
Join Date: Oct 2002
Location: Mississippi
Posts: 3,503
Likes: 0
Received 0 Likes on 0 Posts
I've never done it and I don't know of many people who have, other than experienced transmission shops.
Old 08-16-04, 12:18 PM
  #3  
Seduced by the DARK SIDE

 
SureShot's Avatar
 
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes on 2 Posts
Even with synthetic gear oil, a red line shift will get ahead of a 151K tranny.
Short shifting to 2nd at around 6K max should help.
With the 3.90 rear you can help your final drive ratio with 50 or 45 profile tires on 15" rims.
Old 08-16-04, 12:31 PM
  #4  
Lets rock.

Thread Starter
 
flamin-roids's Avatar
 
Join Date: Apr 2004
Location: SLC, Utah
Posts: 1,355
Likes: 0
Received 0 Likes on 0 Posts
It seems 2nd is the only gear that has shifting problems. If I double clutch it at 6k it shifts fine but if I slam it at 7800rpm it grinds and the tires spin. The reason I'm concerned is the cars powerband seems to be between 6k-8k rpm. Should I just replace the syncro on 2nd or just replace the whole damn thing. Also I'm running 55's on 16 inch rims.
Old 08-16-04, 12:45 PM
  #5  
Seduced by the DARK SIDE

 
SureShot's Avatar
 
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes on 2 Posts
1st gear acceleration is very addictive, so it takes practice nailing 2nd at 6K.
Do you have a g-tech? They are $45 from http://gpsworldsupply.com/gps_world_...oductNum=GTECH
Practice 0-60 runs with the g-tech will tell how you're doing with different techniques.
I still catch myself holding 1st too long.

Next set if tires, drop to maybe 45's

Last edited by SureShot; 08-16-04 at 12:49 PM.
Old 08-16-04, 01:12 PM
  #6  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
Originally Posted by flamin-roids
2nd gear syncro is definitly gone and it shudders at 7k+ shifts.
Good luck - you're going to need it.
No FC trans is going to handle redline shift from 1st to 2nd.
You're going to kill the synchro or the gear itself if you're going to abuse the trans.
The reason this is not possible is due to the numerical gear ratios of 1st versus 2nd gear.
I tend to short shift 1st into 2nd due to this at 6,500RPM.
The other option is to wait a little longer during the shift, which just slows you down.


-Ted
Old 08-16-04, 02:19 PM
  #7  
Seduced by the DARK SIDE

 
SureShot's Avatar
 
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes on 2 Posts
Here is a short video from an autocross.
Launch hard & short shift to 2nd. link to short video
Old 08-16-04, 06:47 PM
  #8  
Lets rock.

Thread Starter
 
flamin-roids's Avatar
 
Join Date: Apr 2004
Location: SLC, Utah
Posts: 1,355
Likes: 0
Received 0 Likes on 0 Posts
So there is no way a TII trans will hold up to 7k rpm 2nd gear shifts? Well how can I mod the trans to run smooth and be able to shift smoothly at 7k+?
Old 08-16-04, 08:15 PM
  #9  
Displacement > Boost

 
88IntegraLS's Avatar
 
Join Date: Oct 2002
Location: Mississippi
Posts: 3,503
Likes: 0
Received 0 Likes on 0 Posts
My na trans takes my 7k shifts from 1-2, but grinds when I take it up to 7.5k.
Old 08-16-04, 08:17 PM
  #10  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
Originally Posted by flamin-roids
So there is no way a TII trans will hold up to 7k rpm 2nd gear shifts? Well how can I mod the trans to run smooth and be able to shift smoothly at 7k+?
No.
Unless you can find a way to swap out the 1st gears to lower numerically (which I am not aware of such a thing exists), it's not possible.


-Ted
Old 08-16-04, 08:39 PM
  #11  
kill it with BOOMSTICK!

 
Falcoms's Avatar
 
Join Date: Mar 2004
Location: McHenry, IL
Posts: 1,227
Likes: 0
Received 0 Likes on 0 Posts
I don't know, my 145,000 mile NA trans takes 8k+ shifts from 1st to 2nd. And that ain't no BS, just incase anyone wants to argue that. If I could mount the digital video camera in the car somewhere while I am driving, I would have proof for ya.
Old 08-16-04, 08:49 PM
  #12  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
Originally Posted by Falcoms
I don't know, my 145,000 mile NA trans takes 8k+ shifts from 1st to 2nd. And that ain't no BS, just incase anyone wants to argue that. If I could mount the digital video camera in the car somewhere while I am driving, I would have proof for ya.
Reread the original post.
We're talking about TURBO transmissions, NOT NA ones...


-Ted
Old 08-16-04, 10:19 PM
  #13  
Lets rock.

Thread Starter
 
flamin-roids's Avatar
 
Join Date: Apr 2004
Location: SLC, Utah
Posts: 1,355
Likes: 0
Received 0 Likes on 0 Posts
So would it be the differences in gear ratios between the N/A trans and the TII trans that makes the shifting differences? The syncro in 2nd is for sure gone because it grinds at any rpm. So I should probably learn better technique going from 1st to 2nd rather than dumping it at 7500rpm. All I want is a smooth drivetrain dammit!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Turblown
Vendor Classifieds
12
10-17-20 03:25 PM
joel(PA)
Group Buy & Product Dev. FD RX-7
8
10-04-15 06:07 PM
FC3S Timmy
2nd Generation Specific (1986-1992)
8
10-02-15 08:08 AM
Smokeyfb33
Old School and Other Rotary
10
10-01-15 12:10 PM



Quick Reply: Drivetrain not holding up



All times are GMT -5. The time now is 06:41 PM.