c6 3rd gear weak?? How to build it better???

[59megawagon]

Hello All: I am tuning on my 9.4 L twin 76mm turboed motor again and am wondering if anyone here has a fix for a weak 3rd gear in a C6? My motor makes 800 ft. LBS. of torque at 2300 RPM and I rip out 3rd gear all the time on the street. Yes my 59 ford ranchwagon 5500 lbs and has huge sticky rear tires so I do know that hurts it more. I run a 3.20 rear gear with a 32" tall tire. I am just wondering if there is any real fix for these trannys or should I just give up on it and build a th400 or a glide???

Thanks for any info.

Tom.

[gregaust]

What valvebody? How many clutches in high/reverse clutch ? What line pressure ? A Frank Merkl valve body and at least 5 clutches as a definite fix

[59megawagon]

Hello: I think high gear only has 3 plates and mine has a thinner steel end plate so I am able to add a 4th friction plate. as for line pressure I dont know? My trans is a 74 lincoln with a long tail shaft. But I think I have a truck valve body with a full manual shift.

[Frank Merkl]

here you go
http://www.460ford.com/forum/showthread.php?t=121505
there is alot of good info in general tech
Frank

[Frank Merkl]

we put 1800 +hp threw our C6's seasons at a time
Frank

[59megawagon]

Originally Posted by Frank Merkl

we put 1800 +hp threw our C6's seasons at a time
Frank

Everyone talks Hp Hp Hp.... all the time but what I am talking about is low RPM torque???? 800 ft lbs of torque at 2300 rpm. I cruise down the road at about 2500 rpm in 3rd gear and floor it and it will rip 3rd gear right out. The transmission pump pressures I would think would be low and would have a harder time holding the torque?? Correct?? I dont care about horsepower... My car makes massive grunt and weights over 2 tons... Will this c6 ever hold up or should I just go to a Glide???

Thanks for any reply.

[Frank Merkl]

Put at stock powerglide or a stock th400 in it like your doing with a stock C6 it will be the same result!!you Need line pressure! a stocker VB with 50@ 2300 psi line pressure isn't going to cut it! you need a VB without modulated pressure ie ; 150 psi @ 750 rpm - 210psi@ 1500rpm and a stock pump it capable of making
Frank

[gregaust]

Before you knock the C6 you need to address what was listed above . Franks info is all there ib the links . 4 frictions won't cut it . You need at least the 5 and a good brand clutch . But even the best components won't live without the line pressures listed above

C6 is more than capable but you at least need to know exactly what's inside the trans for it to have a chance of living

[stuarta]

Originally Posted by 59megawagon

Everyone talks Hp Hp Hp.... all the time but what I am talking about is low RPM torque???? 800 ft lbs of torque at 2300 rpm. I cruise down the road at about 2500 rpm in 3rd gear and floor it and it will rip 3rd gear right out. The transmission pump pressures I would think would be low and would have a harder time holding the torque?? Correct?? I dont care about horsepower... My car makes massive grunt and weights over 2 tons... Will this c6 ever hold up or should I just go to a Glide???

Thanks for any reply.

You need to address what is going on inside.

Valve body and pump are 2 of the main culprits.

If you are flooring it kickdown should happen.

[59megawagon]

Originally Posted by Frank Merkl

Put at stock powerglide or a stock th400 in it like your doing with a stock C6 it will be the same result!!you Need line pressure! a stocker VB with 50@ 2300 psi line pressure isn't going to cut it! you need a VB without modulated pressure ie ; 150 psi @ 750 rpm - 210psi@ 1500rpm and a stock pump it capable of making
Frank

Hello Frank: Thank you for all your input on this thread. You talk about unmodulated line pressure? Are you talking about just not using a vacuum line to the modulator or are you talking about a change in the valve body for a set line pressure??

Thanks for your comments..

[Frank Merkl]

changing the VB to a constant pressure vb
Frank

[59megawagon]

Originally Posted by stuarta

You need to address what is going on inside.

Valve body and pump are 2 of the main culprits.

If you are flooring it kickdown should happen.

I have a full manual VB

[gregaust]

Originally Posted by 59megawagon

I have a full manual VB

Yes , But what type ? And you need to know what pressure it is currently running at .. Some still run modulated line pressure .

[BOSS 429]

Originally Posted by 59megawagon

I have a full manual VB

/\ THAT MEANS NOTHING

I've probaly tried more brands of valve bodys then anyone over the years, FRANKS have been the best. 4 years ago I had 1 company send me 15 to try, drove my trans guy nuts

all junk, Go with frank vb specs

[bigblok86ranger]

Frank I know you have stated how to modify line pressure before but can you add that info to the sticky if you would like to share that info.