Glazing high gear clutches on the street?
#687989
05/04/10 10:10 AM
05/04/10 10:10 AM
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Joined: Jan 2003
Posts: 3,336
Summit, NJ
whiplash
OP
master
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OP
master
Joined: Jan 2003
Posts: 3,336
Summit, NJ
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Just had my trns freshened. 727 behind motor in sig. the trans guy told me that the high gear (3rd) clutches were ok but glazed. He said every high stall converter with a high hp motor on the street glazes the 3rd gear clutches. His reasoning was that the converter is stalling at 3500 rpm and your cruising at 2000, so your always slipping, causing heat and glazing the clutches.
Not wanting to argue with him, I wanted to understand this reasoning more with you guys. I don't necessarily agree with the theory, unless the heat in the fluid around the clutches, not in the pan, gets hotter due to the slipping converter?
Could it be that there isn't enough line pressure at low rpms?
Does the slipping converter effect line pressure?
What do you guys think?
- 67 coronet 4dr, 383/727/GVOD, blown, EFI, daily driver
- 230/238, 114°LSA cam, 1.6 rollers, 9:1 comp, 8 psi boost
- NEW BEST ET - 12.40@110mph...
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Re: Glazing high gear clutches on the street?
[Re: whiplash]
#687990
05/04/10 11:25 AM
05/04/10 11:25 AM
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Joined: Feb 2007
Posts: 5,080
organ
maximum entropy
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master
Joined: Feb 2007
Posts: 5,080
organ
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it would be good to put a temp gauge in that thing, but, the direct clutch may be slipping, which has nothing to do with your converter. is it an automatic valve body? is your throttle pressure linkage adjusted properly? it could be a line pressure issue, inadequate clutch disc clearance, or possibly a clutch piston seal problem, among others. fwiw, i have a "high horsepower high stall" car that gets driven on the street- a lot!
for what is the good life if not doing things thoughtfully?
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Re: Glazing high gear clutches on the street?
[Re: Dragula]
#687992
05/04/10 01:21 PM
05/04/10 01:21 PM
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Joined: Jan 2003
Posts: 3,336
Summit, NJ
whiplash
OP
master
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OP
master
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Summit, NJ
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thanks guys, the above post is how I understand the workings of it. So the glazing could be happening from not enough line pressure, or if the 2-3 shift is not instantaneous.
FWIW, the trans is an auto valve body, deep pan, trans temp gauge never goes above 180 (sending unit in pan), has a cooler on it. The shift linkage is set correctly. The trans itself was originally a TCi super street fighter that I recently had rebuilt(not by TCI), so the VB has some mods to it by TCI.
- 67 coronet 4dr, 383/727/GVOD, blown, EFI, daily driver
- 230/238, 114°LSA cam, 1.6 rollers, 9:1 comp, 8 psi boost
- NEW BEST ET - 12.40@110mph...
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Re: Glazing high gear clutches on the street?
[Re: whiplash]
#687993
05/04/10 01:43 PM
05/04/10 01:43 PM
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Joined: Jan 2003
Posts: 75,012
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,012
U.S.S.A.
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Quote:
thanks guys, the above post is how I understand the workings of it. So the glazing could be happening from not enough line pressure, or if the 2-3 shift is not instantaneous. {b] Only if you have a huge overlap issue and it has alot of miles on it
FWIW, the trans is an auto valve body, deep pan, trans temp gauge never goes above 180 (sending unit in pan), has a cooler on it. The hottest fluid is coming from the convertor , it's the line at the front of the trans , I'd put the sender for your guage there .
The shift linkage is set correctly. The trans itself was originally a TCi super street fighter that I recently had rebuilt(not by TCI), so the VB has some mods to it by TCI. TCI stands for total [Email]CR@P[/Email] Inc.
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Re: Glazing high gear clutches on the street?
[Re: whiplash]
#687995
05/04/10 02:25 PM
05/04/10 02:25 PM
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Joined: Jul 2008
Posts: 30,424
Florida STAYcation
dOrk !
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,424
Florida STAYcation
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Me thimks your trans-guy should go back to school and take ..... Transmissions-101 !  HEAT would contribute-to maybe .5% of glazing of clutches. SLIPPAGE or a severe overlap of the 2/3 shift is the remainder 99.5% of potential probs. Slippage ....due to low line pressure OR worn sealing rings OR leaking rubber seals and/or excessive clutch clearances.
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Re: Glazing high gear clutches on the street?
[Re: whiplash]
#687996
05/04/10 02:35 PM
05/04/10 02:35 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I'm not a trans guy but its not due to the conv... when you are street driving and are taking off with just part throttle your engine isnt making the torque to stall it at the higher stall point so its acting more like a normal conv(it takes torque to have them stall at thew higher point)... might just be the lack of line pressure 
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Re: Glazing high gear clutches on the street?
[Re: whiplash]
#687998
05/04/10 07:55 PM
05/04/10 07:55 PM
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Joined: Nov 2009
Posts: 2,177
ill
dennismopar73
top fuel
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top fuel
Joined: Nov 2009
Posts: 2,177
ill
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never liked tci junk i have hade several buddy had acomplete trans /convert from them bolt in with fluid burned up in less than 300 miles and jegs didnt warrenty it because it went into a 'race car' but i agree with the above line pressure, or miss adj bands  
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Re: Glazing high gear clutches on the street?
[Re: turbobitt]
#688000
05/05/10 01:39 PM
05/05/10 01:39 PM
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Joined: Jan 2003
Posts: 3,336
Summit, NJ
whiplash
OP
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OP
master
Joined: Jan 2003
Posts: 3,336
Summit, NJ
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ok thanks Doc, that's what I was thinking. 2-3 shift overlap due to less than adequate line pressure for whatever reason.
Yes it has the deep pan with the deep pan pickup. It started as a TCI trans, but I had it rebuilt with "better" parts (not getting into whta was changed cause it will cause a pi$$ing match and was not part of the problem).
- 67 coronet 4dr, 383/727/GVOD, blown, EFI, daily driver
- 230/238, 114°LSA cam, 1.6 rollers, 9:1 comp, 8 psi boost
- NEW BEST ET - 12.40@110mph...
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Listen to Doc.