OD worth the $ ?

[Brian VT]

I have 4:10 (C5) axle unless someone has done a swap. 235/85/16 tires.
The few times I was on the highway I drove at 68mph Most folks were going 80mph). I haven't hit the governor but I assume that I was close. The tach. doesn't work.
The heaviest towing I do is my boat twice a year. 3 mile trip each way. lol

So I guess now I'm leaning towards changing gearing. I don't know what's involved for a 4wd.

 

[Rdnck84_03]

So I guess now I'm leaning towards changing gearing. I don't know what's involved for a 4wd.

Easiest way is to swap both complete axles.

James

 

[Brian VT]

Thanks.
Will I still have the issue with the torque converter (slippage and heat)?

 

[Black dawg]

Torque converter generating heat is always a problem with the c6. Will be fine with 3.54 gears. My recommendation would be to have someone re gear the rear for you, and fine a used front differential. Dont need the whole thing, just the center section.

If you could find a used 10.25 with 3.54 gears, that would be an ok way to go, but they seem to be rare and I would plan on taking it completely apart unless it was really low miles. Found one recently that had 50k on it......

 

[david85]

One question is how often do you drive on the highway? Taller gears won't help your MPG if you seldom go over 40MPH. Lower gears actually help you get off the line in stop and go traffic.

 

[Rdnck84_03]

Dont need the whole thing, just the center section.

I would say that if ball joints and everything are good in the donor that the full swap is much easier.

Been a long time since I have torn into a ttb axle so correct me if I'm wrong but don't you have to pull at least one spindle and axle shaft out to get the center section out?

James

 

[Brian VT]

One question is how often do you drive on the highway? Taller gears won't help your MPG if you seldom go over 40MPH. Lower gears actually help you get off the line in stop and go traffic.

I avoid the highway. Probably only once a month or so. And usually not more than 30-60 miles.
Locally the main road is posted at 50mph and we usually go 60mph. Usually doing stretches of 5-10 miles. A few times per week.
So it's not unbearable. And MPG isn't a concern.
Do you think I would regret the gearing swap?

Maybe I'm over-reacting to the RPM thing and should just get taller tires? I am due for a new set.

 

[Black dawg]

I would say that if ball joints and everything are good in the donor that the full swap is much easier.

Been a long time since I have torn into a ttb axle so correct me if I'm wrong but don't you have to pull at least one spindle and axle shaft out to get the center section out?

James

Easiest way is to unbolt whole left side section (pivot bolt and u bolts) and slide it off of the right side axle. Due to alignment issues I wouldnt re use any used ttb stuff, just replace the center.

 

[papadiesel]

if

 

[Rdnck84_03]

I went from 4.10 to 3.54 with I believe 285/75- 16 and a t19 it cruise nice on the highway, but I did notice that if on a slight grade taking off now that it doesn't like second gear takeoff. I do plan to eventually put a zf5 in.

 

[Nero]

Also note, doing the ball joints in a ttb isn't that hard, I rebuilt a D50 I swapped into a F250 once, was fairly easy.

If you rarely drive freeway, I'd leave it as is. Maybe put a big monster trans cooler on and call it a day.

 

[u2slow]

@Brian VT I would try the taller tires. I do that to most of my trucks just for better load capacity. 285/75R16 fits the 7" wide wheels nicely. Shouldnt need to lift anything; maybe shim the bumper out.

If you could find a used 10.25 with 3.54 gears, that would be an ok way to go, but they seem to be rare

Probably a 2:1 bias of 3.54 commonly showing up in trucks I've wrenched on or parted out.

Maybe the overall odds are more like flipping a coin.

 

[Black dawg]

@Brian VT I would try the taller tires. I do that to most of my trucks just for better load capacity. 285/75R16 fits the 7" wide wheels nicely. Shouldnt need to lift anything; maybe shim the bumper out.




Probably a 2:1 bias of 3.54 commonly showing up in trucks I've wrenched on or parted out.

Maybe the overall odds are more like flipping a coin.

Around here, 3.54 is probably more common than 4.10 in the dana rear trucks. But I have seen very few 3.54 ratio 10.25 trucks.

 

[Rdnck84_03]

I may have found the odd trucks but I have had 2 bricknose f250 4x4 trucks with a 351w zf5 with 3.54 gears.

James

 

[Old Goat]

I went from 4.10 to 3.54 with I believe 285/75- 16 and a t19 it cruise nice on the highway, but I did notice that if on a slight grade taking off now that it doesn't like second gear takeoff. I do plan to eventually put a zf5 in.

I guess you are referring to your 83 in your Sig.?

My 86 is a T-19 with 3:55 Diff., and 235/85/16.
I always start in 1st gear, then go to 3rd on the flat. On a slight down grade might start in 2nd.
2nd seems to be a bit too high to start in.
Starting out on a up hill grade with a load, or car Trailer, get started in 1st with the 3:55, is a bit of a challenge. Have to play with the Clutch to get her rolling.

With your 285/75 the tire is a bit shorter than the 235/85, so starting in 2nd is probably easier to get rolling. But with the 75`s the engine will spin over a bit faster at speed.

Couple summers back was at PNP and saw a 97 Van sitting in line to be processed. Looked to have the grey steel rims. Asked the MGR. anyway I could get those as they just throw them in the steel scrap Dumpster.
They Fork lifted it up front to remove them, then noticed the Hub Caps. Asked if I could but Tires and all? $350 out the door. Figured a set of good rollers for my other truck sitting in the yard.
After looking at them were in good shape, plenty of tread and Coopers which I use.

I threw them on the rear of my 86, and noticed the engine running at a higher RPM. So now run them on the front.
They are 245/75/16.

Thee are weak points on the ZF you mention.
The T-19 is probably a tougher trans. The weak point I read about is the Aluminum Bell Housing developing a crack. I have seen a few pictures posted.
I do have a spare I got at PNP a few years ago.
(can`t have too many spare parts)
But nothing if totally bullet proof.

A T-19 and a GV would be a good combo for the OD, but still not give any low start gear.

Best is a T-19 and a 3 spd brownie.
HMMM... and I do have one of those.

I can see where Brian`s C-6 slip-a-matic and a GV might not give the total performance he is looking for.


Goat