700R4 nightmares

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Vbb199

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I think I have 3.73 stocks in the rear, would 4.10 or 4.56 improve the 35” tire problem?
I can rebuild an engine or build ya a house, but Trani and gears are not my wheelhouse.
Thanks everybody!
Woody
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Woody Burban

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In checking records, stock it may have 3.42’s in the rear. Could that be cooking my trani? I don’t care about gas mileage 4.56 maybe the best based upon this chart, I tow quite a bit too.
 

CheemsK1500

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In checking records, stock it may have 3.42’s in the rear. Could that be cooking my trani? I don’t care about gas mileage 4.56 maybe the best based upon this chart, I tow quite a bit too.
I have a Jeep with 35 inch wheels, and a 4:56 rear end. It is plenty powerful, though it is equipped with a 4 speed manual, so RPMS remain at a constant high. If you go that low of gear, I recommend at least a five speed transmission.
 

Frankenchevy

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The 700r4 has a .75 OD correct? Yeah, 4.56s would be perfect with 35s. A 3.42 or 3.73 is no good for your OD and tire size.

I want to do 4.56 gears with my nv4500 and jump up to 35” tires. For now I have 3.73s and 33” tires. Too tall of a combo, but the manual trans can work around it.

Is the 700 still under warranty?
 

Frankenchevy

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I think @82sbshortbed got a 700 from jegs. I don’t know if it’s installed yet.

The price seemed reasonable. You could regear just the rear axle for now, but remember to not use 4wd at all. What transfer case do you have?
 

shiftpro

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I think I have 3.73 stocks in the rear, would 4.10 or 4.56 improve the 35” tire problem?
I can rebuild an engine or build ya a house, but Trani and gears are not my wheelhouse.
Thanks everybody!
Woody
There's your problem right there. Your lugging the transmission. NOT the way to keep a 700 alive. 199er just mentioned it above.
 

82sbshortbed

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I think @82sbshortbed got a 700 from jegs. I don’t know if it’s installed yet.

The price seemed reasonable. You could regear just the rear axle for now, but remember to not use 4wd at all. What transfer case do you have?
Its supposed to be delivered on the 15th thus week. Let's hope so. I also have a 3.73 posi rear end in it also. Reason I need the od. It was 2k to put it in the driveway. Better than 70k lol
 

Woody Burban

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I can feel the heat on the floor in the bell housing. ahhhHghah!
Perfect!
I’ll regear to 4:56 and I think I have to match front gears to rear gears, rite?
No 4x4 till matched. Is it worth putting a G80 or Tru Trac at the same time? I only want to do this once more! Has a stock posi rear now, looks like a tooth pick holding up a snapping turtle!
Can I just buy an old set of military 2500/3500 axles Full Float and make em fit. Move it from a 1500 to 3500 now!
I already releafed rear to a 3500 rear leaf set.
Thanks guys I owe ya a coffee!
Woody
 

Vbb199

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The aforementioned military 3500 axles are 5/4 ton axles , from a cucv.

Kingpin Dana 60 front (sometimes trak-lok)
14 bolt full float rear end (detroit locker usually always)
4.56 geared.

You'll have to do something with your steering to make it work (larger TRE), and you'll need at least a 16.5 wheel to clear the bigger brakes. And a bigger master cylinder.


If this is street driven you won't be a big big fan of the Detroit on pavement

We still have no earthly idea what's under the hood, but presumably if it's just a stock 350 or something?

A set of 1 tons would be cool af, but maybe not with a detroit.

Something that's a clutch type locker would be more agreeable on the street.


And 3500 leafs in the back?
:oops:

I'm sure that's a blast to drive
 

CheemsK1500

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You don't need 1 ton axles for low gears, though they do have much stronger internals. My Jeep has them crammed into the factory Dana 30 front and AMC 20 rear. With that being said, there are plenty of low geared 1/2 tons and smaller SUVs that survive just fine with their factory axles.

Unless you often go rock crawling, play in the mud, or plan on doing a diesel swap, your factory axles will work just fine.
 

SquareRoot

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I have the early (93) NV4500 in my truck with stock 31" tires and 4:10 gears. Overall, it's a good combination. I have the 4:56 axle sitting in the garage waiting for me to remove that OBNOXIOUS Detroit Locker before I put it back in with open gears (for now). Off road there's no other locker I would want. But, 90% of my driving is on road and the Detroit paired with a MANUAL transmission is terrible. It was fine before with the auto but not the manual. Without a torque convertor absorbing the ratcheting nonsense in the locker it transfers thru the drivetrain and feels like he!!.

I also have a rare early model (94) NV4500 with the higher gears and removable top cover that will be going in soon. It's also better suited for the street. As is, I start off in second and have to shift to third before I get thru the light. Once I get the 4:56 gears, newer model NV4500 and a True Trak LS in all will be perfect! It's taken a lot of trial and error and.....money to get it right, but that's hot-rodding!
 

Frankenchevy

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I believe all SRW CUCVs have 16” wheels from the factory. The factory 16s clear the 1-ton brakes.

A d60 in very used condition will be more than regearing both axles.
 

MikeB

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35" tires with 3.73 should work well with a TH350 or TH400, at least on the highway. RPM vs. MPH is almost exactly like a 29" tire (255-70x15) with a 3.08 axle, which has worked fine on my 69 C10 for for 30+ years. Now if you plan to do off-roading, a 3.73 and your 35" tires may not be a good combo.
 

Galane

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I rebuilt it 1st time with a Monster Kit and 1650 stall Tourque converter. Blew valve, shredded it. I rebuilt it again, had trouble shifting 2-3rd. Replaced TV cable, adjusted it with pan open, made sure compressed perfect. Drove and tuned it. 1,000 miles began jumping 4-3 and ran it just in 3rd, then heavy vibration on highway at 1800 RPM. Blew 4 & 3 today.

I’m so F’ing tired of this issue, it’s only a 1500 and my mechanic said the 35” tires may be to much for the trani.

Now I need to get it on the road again. I was gonna buy a reman, Monster Trani 700R4 and stock torque converter and drop it in.

At this point Ive though about just moving to Standard! Is this possible.

Any ideas? 460LE?
Thanks
Woody

What did you do for the shifter to have it work right with the extra positions? I have a 700-R4 in an 82 GMC and swapped in a tilt column that was supposed to be from a Suburban with a 700-R4. Hah. Probably was one that had been swapped in place of a TH350. I can get its notches to align with any one gear, neutral or park while nothing else aligns.

Sure would be nice if some company would get with it and make retrofit 4 speed kits for the 1980's 3 speed columns like they do for the 60's and 70's with the indicator on the column. There are no more 80's 4 speed columns to be had, they're always gone the instant a factory 700-R4 truck hits a junkyard.
 

ak4life

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I rebuilt it 1st time with a Monster Kit and 1650 stall Tourque converter. Blew valve, shredded it. I rebuilt it again, had trouble shifting 2-3rd. Replaced TV cable, adjusted it with pan open, made sure compressed perfect. Drove and tuned it. 1,000 miles began jumping 4-3 and ran it just in 3rd, then heavy vibration on highway at 1800 RPM. Blew 4 & 3 today.

I’m so F’ing tired of this issue, it’s only a 1500 and my mechanic said the 35” tires may be to much for the trani.

Now I need to get it on the road again. I was gonna buy a reman, Monster Trani 700R4 and stock torque converter and drop it in.

At this point Ive though about just moving to Standard! Is this possible.

Any ideas? 460LE?
Thanks
Woody
4l80e !
 

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