th400 to 700r4 for a m1009

[84cucv1ton]

just want to know a few things. i was just going to drop in the 700r4 and the 241. all bolted together and works fine. i know i need a new torque converter. witch one tho? also what about the lock up on the trans? being its going into a truck with out a computer. anything i missed please clue me in

thanks

 

[CCATLETT1984]

you can wire the lockup to a switch, you need a diesel torque convertor.

 

[Croatan_Kid]

I just did a 700R4/NP208 swap in my M1008. You will need:

Flexplate for a 1980 whatever K5 with a 6.2/700R4
torque converter
a diesel governor for the trans
torque converter bolts
a lockup kit (I highly recommend Bowtie Overdrives!)
a 700R4/6.2 TV cable bracket and rod
dipstick if you dont have one


I think that's about it!

 

[Rocco]

Whats a" lock up"??

 

[Croatan_Kid]

At speeds about 35 MPH the torque converter clutch locks together. This creates a direct connection between engine and transmission. Better on gas/fuel, cuts down immensely on heat build up in the transmission because it eliminates torque converter slippage, and it makes everything last longer because of less heat. Pretty cool stuff.

The clutch in the torque converter is in a normally locked position, but when the vehicle is running and the pump is pumping, the fluid pressure makes the clutches spread apart. When the transmission is within range to lockup, the solenoid in the bottom of the pump shuts off fluid flow and lets the clutch lock together.


Anything else? That was an easy one!

 

[mutt1966]

If anyone has done this swap in a M1009 leaving the gearing at 3:08 was there a significant increase in MPG Ive been thinking of doing it but if its only a mile or two I dont think I would, anyone with any input. I have the trans and everything out of 86 Jimmy 6.2 to use Tnaks Scott

 

[crusty]

Seems to me that 3.08 is pretty tall for an OD. What is the standard gear from the 86 Jimmy 6.2?

 

[1-tonmudder]

I have saw them with 3:08's and 3:42's.The 700/3:08 combo might be a economical choice but they make for a turd to drive.I have no data to prove it but I would think the 700 would work better with some 3:73's.

 

[mutt1966]

the gearing in the jimmy was 3:73 there was another option of 4:11 if you were going for the towing package, without the towing package 3:08 was avalabile. The 700R4 has a lower 1st gear so it should be alright getting up to speed.

 

[AJMBLAZER]

GM put the 3.08's in everything. That effort to get as much mpg out of everything as possible even at the expense of drive-ability and mechanical common sense.

You wanna see a turd try a 89 K5 with the 350, a 700R4, 29" tall tires, and 2.73 gears!

 

[crusty]

I don't think an 86 Jimmy diesel would have a lockup converter. Anybody know for sure?

 

[Croatan_Kid]

All 700s were wired for lockup to the best of my knowledge. It's just the nature of the transmission to make it work for maximum longevity and performance.


I must agree....my dad's K-10 with a 350/700R4 has 3.08s and it gets 10 MPG! At 55 MPH in 4th gear it's only turning 1400 RPM which I'm sure is lugging the motor down. He also had a 79 K-10 with a 350/465 4spd and 3.07s that got 16. Sometimes OD gear is too much, but I think the M1009 will be fine with 3.08s. Not a speed demon for sure, but it'll get good milage. A guy I work with gets 24 MPG in his Suburban with a 700 and 3.08s.


Maybe Magnus will chime in....I think he's had this swap done for quite a while!

 

[84cucv1ton]

this is my fathers idea. he was going to sell it. great truck tho. got a mess load of parts for it too. 6.5 turbo and serp set up. 4" lift springs. more to come

the 700 is from a 90 k5 with a 5.7. was going to put the 700/241 right in. this is some good info. thanks for the help guys

 

[84cucv1ton]

what torque converter should i go with?

 

[AJMBLAZER]

There was a big discussion on this over on CK5 in the diesel forum a while ago. I think it was one of MaxPF's threads.

Croatan also got into this a bit in his thread on here.

 

[CCATLETT1984]

Maybe Magnus will chime in....I think he's had this swap done for quite a while!

ROTFL

he has the gears but doesnt have them in the truck

 

[Croatan_Kid]

I was talkin about the general idea of having a 700R4...geez!


I used a torque converter from Alpine Transmissions, they have a store on Ebay. I think it was 125 bucks or so, don't remember if they had free shipping or not, but I want to say they did. So long as it's a low stall I don't think it matters.

 

[84cucv1ton]

thanks

 

[84cucv1ton]

getting ready to do this now. i have a complete set up from a 85 k5. for 300. would i be better finding a newer 700??

thanks

 

[84cucv1ton]

anyone?