need decoding help torque converter

[jimski]

I bought a torque converter from here on the site was a rebuilt unit.Curious to know if it is lockup or not It has 5's stamped all the way around so it is a 2800 stall right? But im not sure if it is lockup or not.Heres the numbers, CBCF 8656954 981210

 

[mikestertwo]

I bought a torque converter from here on the site was a rebuilt unit.Curious to know if it is lockup or not It has 5's stamped all the way around so it is a 2800 stall right? But im not sure if it is lockup or not.Heres the numbers, CBCF 8656954 981210

Sounds like a stock D5 unit. Stall should be in the 2000-2200rpm range unless it was modified. Should also be a lockup. If it still has the stock sticker on it I doubt it was rebuilt unless it is a factory rebuild.

 

[jimski]

Sounds like a stock D5 unit. Stall should be in the 2000-2200rpm range unless it was modified. Should also be a lockup. If it still has the stock sticker on it I doubt it was rebuilt unless it is a factory rebuild.

it does not have d on it thou just 5's all that way around it and the sticker says remfd.. for gm made in u.s.a
cbcf is the first 4 letters on the sticker then comes 8656954 then 981210

 

[blackplague]

Here is what it means!

it does not have d on it thou just 5's all that way around it and the sticker says remfd.. for gm made in u.s.a
cbcf is the first 4 letters on the sticker then comes 8656954 then 981210

C = 200c,2004r,pre '85 700r4,325-4L (27 spline)

B= 2025 Stall speed

C= 330# step rate lock up clutch and damper

F= lock up 3 lug


So basically you have a re-manned D5

Mike.

 

[jimski]

C = 200c,2004r,pre '85 700r4,325-4L (27 spline)

B= 2025 Stall speed

C= 330# step rate lock up clutch and damper

F= lock up 3 lug


So basically you have a re-manned D5

Mike.

Thanks for solving this mystery for me.

 

[Turbo F-bird]

I have a CB8F 8656957 982807 GM reman on my shelf. It has 5's around the outer perimeter too. Is this just a reman D5 too?

 

[blackplague]

Yes, But

I have a CB8F 8656957 982807 GM reman on my shelf. It has 5's around the outer perimeter too. Is this just a reman D5 too?

The #8 on the tag means the lock up disc has the 300# step rate clutch damper.

 

[Turbo F-bird]

So that means mine has less ''holding strength'' when it locks up than the 8656954 at the beginning of the thread?

 

[blackplague]

It's not holding power.

It's dampening power. The lock up disc looks just like a one sided clutch disc with dampening springs. It's the rate on the dampening springs is what the 3rd number on the tag indicates in the 298mm family.

Mike.

 

[Turbo F-bird]

Oh I get you. It's like the springs in the hub of a clutch disc for a standard trans car right?

 

[blackplague]

Exactly!!!

Yes !!!

 

[chris718]

Mike can we get a thorough explanation of what is used in what?Thanks.

 

[chris718]

 

[GNeric]

According to my GM literature, the 4 digit code would break down as:
1st digit

B- 250 and 350 transmission
C- 200/2004R/Pre '85 700R4 with 27 spline input
D- '85 and later 700R4 with 30 spline input

2nd digit
"K" factor-engineering term that means the speed of one member divided by the square root of the torque on the same member. This is calculated at stall conditions.. On a 298mm torque converter, you can multiply the "K" factor by 14.2574 to get the stall speed.

A= 142=2024 stall
B= 140=1996 stall
C= 135=1925 stall
D= 130=1853 stall
E= 115=1639 stall
F= 110=1568 stall
G= 100=1425 stall
H= 97=1383 stall
J= 89=1269 stall
K= 85=1211 stall

3rd digit

0 = No clutch
1 = 300ft/lb 43 degrees of travel
2 = 240ft/lb 46 degrees of travel
3 = 290ft/lb 44 degrees of travel
4 = 160ft/lb 37 degrees of travel
5 = 220ft/lb 35 degrees of travel
6 = 195ft/lb 42 degrees of travel
7 = 195ft/lb 30 degrees of travel
8 = 300ft/lb 44 degrees of travel
9 = 290ft/lb 44 degrees of travel
A = 300ft/lb 29 degrees of travel
B = 300ft/lb 44 degrees of travel
C = 330ft/lb 28 degrees of travel

4th digit
cover style and number of mounting lugs and method of welding

A = open cover (no clutch), 3 lugs with one weld per lug (gas)
B = open cover (no clutch) 3 lugs with three welds per lug (diesel)
C = converter clutch type, 3 lugs with one weld per lug (gas)
D = converter clutch type, 3 lugs with 180 degree weld on each lug (diesel)
E = converter clutch type, 6 lugs with 180 degree weld on each lug (diesel)
F = converter clutch type, 3 lugs 245mm style lug

Hope this helps.

 

[blackplague]

What I see mostly in

Monte ss and Gn/Ttype is the #8 clutch/damper assy which gives you up to 44 degrees of crankshaft rotation and 300# springs to dampen the inital engagment of the lock up disc and once the disc is locked, it dampens the engine firing pulses. Most of the new Vig and Yank offerings have a billet disc with no damper to dampen the engagement or firing pulses (hot rod stuff).


Mike.