Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
Sponsored by:
Sponsored by:

Tranny issues

Thread Tools
 
Search this Thread
 
Old 05-11-2006, 02:13 PM
  #1  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default Tranny issues

I had a probuilt transmission kit done to my tranny. At first I thought all was well but the more I payed attention the more I started noticing little issues. I noticed that going from N to D I get a hard push for some reason. Also the shifts were very soft. You actually had to be paying attention to even know it shifted. And last but not least there are times when the car will not shift from first gear.
We traced that to the vacuum hose in the T. For some reason it bends and prevents it from shifting I guess. First thing we did was get a new seperator plate and re-drill smaller holes. Then we installed high performance Superior intermediate billet servo, a high performance Superior overdrive billet servo and that's when everything went bad.
On the first test drive the car felt like it had no power and it shifted 1000 rpm's earlier than it did before. Also the shifts became softer. Now were going back to the servos that came with the probuilt kit but I still dont know what to do about the horribly soft shifts. Any input would be great because Im this close to giving up on this POS.
Old 05-11-2006, 04:52 PM
  #2  
Banned
iTrader: (3)
 
8a8mfh's Avatar
 
Join Date: Feb 2006
Posts: 1,943
Likes: 0
Received 0 Likes on 0 Posts
Default

So you had a kit done such as rebuild kit?
Who put that in? Was everything air tested? what did the 3-4 clearance end up at? what did the band clearance end up at? what did a line pressure check reveal? What year is the transmission?
Did you do a converter at the same time?
Old 05-11-2006, 07:50 PM
  #3  
Banned
iTrader: (-2)
 
Rock-On's Avatar
 
Join Date: Nov 2003
Posts: 271
Likes: 0
Received 0 Likes on 0 Posts
Default

soft shifts = low pressure, check your line pressure....tell your guy to get back to basics I think you can salvage this ...but like 8a8mfh has stated you've gotta check a few things, and know what these clearances are.... get rid of that small hose(vacuum hose ) an get a good quality 1/4 inch air/hyd. hose(something that will not bend), or steel tubing for your vacuum supply line, trapped vacume will give you the results you have discribed... while your at it dissconect the vacuum supply it'll go to full line ..Thats an easy check...Hope this helpd ..Dave
Old 05-12-2006, 05:04 AM
  #4  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Ill get all the info from my tranny guy and post back. thanks for the replies.
Old 05-12-2006, 11:56 AM
  #5  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by 8a8mfh
So you had a kit done such as rebuild kit?
Who put that in? Was everything air tested? what did the 3-4 clearance end up at? what did the band clearance end up at? what did a line pressure check reveal? What year is the transmission?
Did you do a converter at the same time?
The 3-4 pack clearance was 0.03", the band clearance was about 0.12". It's a 1994 tranny. We have no way of checking the pressure. How does one adjust the vacuum modulator?
Old 05-12-2006, 02:40 PM
  #6  
Banned
iTrader: (3)
 
8a8mfh's Avatar
 
Join Date: Feb 2006
Posts: 1,943
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Honda Hunter
The 3-4 pack clearance was 0.03", the band clearance was about 0.12". It's a 1994 tranny. We have no way of checking the pressure. How does one adjust the vacuum modulator?
If you cannot check the pressure you (or whoever) should not be rebuilding transmissions.

Did you call and get these numbers for the clearances? Sounds like the generic "this is what they should be so tell him that" answer.
You don't adjust the modulator on a 4L60E, there is a screw in the nipple but thats not to be touched. During assembly any adjustments are made by grinding the pin size.

Never installed my vac mod kit but the higher the stall speed the shorter the pin, I would assume the pin was installed as is and needs to be shortened.
Old 05-12-2006, 02:47 PM
  #7  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Shortened how much? Also what tool is needed to measure the pressure?
Old 05-12-2006, 05:15 PM
  #8  
Banned
iTrader: (-2)
 
Rock-On's Avatar
 
Join Date: Nov 2003
Posts: 271
Likes: 0
Received 0 Likes on 0 Posts
Default

Reduceing the pin lenght reduces the pressure.....try removing the hose thereby putting it @ 0 vacuum, read the pressure..... you should get max line...no more than 230 max in drive....you'll need a gage that will show 0-400 psi....I wouldn't touch the pin till you get a reading on the line pressure....hope this helps Dave
Old 05-12-2006, 05:31 PM
  #9  
Banned
iTrader: (3)
 
8a8mfh's Avatar
 
Join Date: Feb 2006
Posts: 1,943
Likes: 0
Received 0 Likes on 0 Posts
Default

Reduceing the pin lenght reduces the pressure
That makes sense when you think about it, I forgot.
Old 05-12-2006, 11:58 PM
  #10  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

If I remove the line at the T it wont shift. Which are you refering to?
Old 05-13-2006, 12:08 AM
  #11  
TECH Addict
iTrader: (9)
 
buffman's Avatar
 
Join Date: Nov 2004
Location: Kzoo, MI
Posts: 2,289
Likes: 0
Received 0 Likes on 0 Posts

Default

Pressure can be tested here
Old 05-13-2006, 12:10 AM
  #12  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Awesome. What tool is used to measure it?
Old 05-13-2006, 07:06 PM
  #13  
Banned
iTrader: (-2)
 
Rock-On's Avatar
 
Join Date: Nov 2003
Posts: 271
Likes: 0
Received 0 Likes on 0 Posts
Default

If you remove the vacuum line at the "T" it'll throw the trans into HI line...and it will shift after that...you'll have max pressure....You'll need a hyd. pressure gage that goes from 0-400 psi....hope this helps Dave.... (nice pic of the service port)
Old 05-13-2006, 07:11 PM
  #14  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by Rock-On
If you remove the vacuum line at the "T" it'll throw the trans into HI line...and it will shift after that...you'll have max pressure....You'll need a hyd. pressure gage that goes from 0-400 psi....hope this helps Dave.... (nice pic of the service port)
I dont understand how that would put it in HI line. When that hose bends it wont even shift so I'm confused how it would shift harder if removed? Thanks for all the advise so far guys. So far with the new plate and old servos that came with the kit I'm told it's shifting better, at least better than it was. Ill test it in the morning. Why does it jerk when I go from Park to drive also?
Old 05-16-2006, 08:19 AM
  #15  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

What should the line pressure be at?
Old 05-16-2006, 10:23 AM
  #16  
Banned
iTrader: (-2)
 
Rock-On's Avatar
 
Join Date: Nov 2003
Posts: 271
Likes: 0
Received 0 Likes on 0 Posts
Default

Hey , When your hose kinks, theres a chance that it will trap low vacuum below the kink, therefore because of the kink, it will not allow the modulator to go to full line...or 0 vacuum, ergo the soft long low pressure shifts. Pressures should read say 90 psi @ idle, to 230 wot in drive, and 140 idle to 300 wot in reverse, or there abouts , also becareful and make sure line pressure matchs foot travel(in other words the pressure has to snap up and down, matching foot travel)...hope this helps Dave
Old 05-16-2006, 02:37 PM
  #17  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Good ifo, thanks. Right now my TPS sensor is giving me issues so I must replace it and see if it shifts normal. I need to find something fast to check the line pressure.
Old 05-19-2006, 07:27 PM
  #18  
TECH Addict
Thread Starter
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Got it all figured out. Replaced the hose, and tps sensor and it seemed to work out. Shifts still arent neck snapping but screw it, it shifts and that's all that matter. My next and final question is what's the difference between the stock seperator plate and the Transgo seperator plate ? When we replaced mine we used a stock one and redrilled the holes. Should we have used a transgo seperator plate? Thanks everyone for all the help. On a side note, I noticed with old hose whenever it kinked the trans temp would shoot to 195 easy is there a reason for this?
Old 05-20-2006, 06:02 AM
  #19  
11 Second Club
iTrader: (9)
 
Greaseymec's Avatar
 
Join Date: Apr 2005
Location: San Antonio
Posts: 452
Likes: 0
Received 1 Like on 1 Post

Default

With the hose kinked, there is a good chance that there was trapped vaccum in the line. This would will translate into low line pressures because the modulator is "seeing" vaccum. Not a problem when at lower throttle settings but when you apply power and the vaccum mod has set low line pressure you will have some slipping clutches, which in turn creates heat and heats the fluid. Then you see the result as increased fluid temp. Glad you got the issues worked out.

Mec
Old 05-20-2006, 07:43 AM
  #20  
Banned
iTrader: (3)
 
8a8mfh's Avatar
 
Join Date: Feb 2006
Posts: 1,943
Likes: 0
Received 0 Likes on 0 Posts
Default

what's the difference between the stock seperator plate and the Transgo seperator plate ?
The steel that the transgo plate is made of is harder, this helps around where the check ***** are, some plates get beat up where the ***** are.



All times are GMT -5. The time now is 12:31 PM.