73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: MohterTrucker on November 22, 2009, 01:55:53 pm
-
For the resident trans experts I have two questions:
1: I have a burnt-out 27 spline 700r4. Should I bother with a rebuild/upgrade for what will be mostly a tow rig.
2: How do I properly adjust the governor in a 700r4?
A little backstory if you care to keep reading:
I burnt out the trans in my truck towing a camper trailer when the TV cable came un-adjusted (don't ask). I replaced it w/ a craigslist special. After installing the proper TV cable geometry bracket on my carb and adjusting the cable it still shifts early (~4200 rpm @ WOT). The trans currenty in the truck is a factory replacement 30spline supposedly bought from a dealer and has low miles (~10k). The shift are nice and firm and generally works well, except for the early shifts.
I'm also planning to increase the output of my engine to somewhere around 5450hp/lot-o-tq in the future. Would the 27 spline trans w/ rebuild/upgrade stand up?
Advice/input appreciated!
-
What year is your burnt 700? If its a newer one, definitely rebuild it. I don't know how much a stock 700R4 will handle, but mine is moderately built, and the trans shop said it would handle up to 600 hp
-
Well a 5450 HP engine certainly would kill a 700R4 so maybe you should think about a hyperdrive system like the Millenium Falcon used.
So what engine are you planning on putting in front of your 700R4?
-
iff your looking at 500+hp sounds like a BBC and towing
either convert to manual or a 4L85E th400+ gear venoder would work to..
700r4 aint up to the task just the weight of the truck allone and that much power would put a serious hurting on a 700
-
Haha. Fifty-hundred forty five! Thats my kids current favorite number.
What I meant was 450. Single turbo TPI 355. The original trans was, i think, the original '83 trans.
Any tips on the gov calibration?
-
Try to tighten the TV cable more. The only thing you can do with the governor is change the springs but I think you just need to tighten that tv cable.
-
Well a 5450 HP engine certainly would kill a 700R4 so maybe you should think about a hyperdrive system like the Millenium Falcon used
lol :D
Haha. Fifty-hundred forty five! Thats my kids current favorite number.
My boy's favorite time is 30 o'clock and his favorite number eleventeen, you know, the number after ten.
-
Try to tighten the TV cable more. The only thing you can do with the governor is change the springs but I think you just need to tighten that tv cable.
I went one notch tighter on the cable and it shifts a little harder but no change in rpm. Everything I've read and heard makes me weary to have it out of 'proper' adjustment to far. Especially after burning up the old trans.
The 'new' trans did cause my speedo to read under. I wonder if its geared higher and if that would affect the shift rpm.
-
No, keep going tighter to get a later shift. Loose is what you don't want.
-
I tightened the cable a couple days ago, but its been so rainy here that I couldn't get any good WOT runs to check the shift points. But I did yesterday and w/ the cable two notches tighter it seems like the shifts are delayed a split second in normal driving. At WOT from a stop it'll shift into second at ~3800 and third ~4100rpm. It shifts nice and hard but that still seems early to me.
-
Tighten the cable up all the way and work from there.
-
At WOT from a stop it'll shift into second at ~3800 and third ~4100rpm. It shifts nice and hard but that still seems early to me.
That's about what mine does and I run max TV adjustment (pull the adjuster all the way back and then push accelerator down to the floor).
-
Thanks for your help, guys. It sounds like I've been going about the adjustment the wrong way. I'll try starting from the 'tighter' side and see how it works.