My two trucks, an 88 and 93 both have 3.55s...

Also, if your 3.55 truck pulls better than the one with 4.10's you need to tune up the 4.10 truck bigtime. Mileage of course will be better when empty with 3.55's but when loaded you'll be happier with 4.10's

 

Yeah, the 4.10 truck needs work, a lot of work. I need to pull the interior and weld the passenger side floor that is pretty cracked up.
I live in cold climate (WY/MT), but because the closest town is 35 miles away, Things get warm before I shut the truck off. I should mention that in the 35 -40 miles trip there is only 1 stop sign.
I re-geared the truck and put 3.55's in it, in an effort to help fuel mileage and reduce highway noise. Now that I have a trans with a lower 1st and 2nd gear, I hope it will work out better.

 

Did you have any problems putting the gas gears in there? I've been looking for a wide ratio diesel for a long time but could get my hands on a 460 zf. My gut tells me it should work because factories favor interchangeability, but stumbled across this post and thought I better check with someone who has done it.

 

So easy a caveman could do it! You will have to change them all, you can't use 1st and 2nd from a gas set and the rest from a diesel set (I tried to go that route ).
I have heard that a 460 ZF will go behind a 7.3 (with a little modification) but have never tried it.

 

RacinNDrummin did it; that's what he had in the Bronco.
IIRC, it's just drilling a few bolt-holes in the casting. You probably pull the adaptor plate off the back of the engine, get it lined up on the front of the ZF(out of the vehicle) and use that as a template for where the holes are. Then just drill em out and install.

 

I don't think I could bring myself to drill it out, especially with increased risk of cracking the bellhousing. My truck will be used to haul bales through pastures as well as gross 30,000+ pounds after the motor is rebuilt. More importantly my old man has a few 73-79 pickups that would be too cool with a five speed so it's a win win to swap gears. Where did you order the replacement gears from?

 

I'll have to dig it out. It was a favorite on my old computer, but that one crashed!

 

You do know it's the same casting, though? The only differences between 460 and idi was which set of holes were drilled? IIRC...

Cracking the bellhousing isn't really a problem, unless you have a DMF flywheel which explodes. That can easily crack the bellhousing.

Other than that, it's surprisingly hard to do... I've abused my truck prior to my current build and when I took it apart to rebuild my engine, I found that I had forgotten to install 1 of the 6 bolts holding the transmission on, and a second bolt was too long and wasn't holding anything.

Took it off and everything was just fine.

That being said... If you intend to gross 30K, you'd better get a R&D IP and good turbo on there. That takes /power/. I hauled 16K+7K truck = 23K, and that was a heavy load even making >240RWHP.
You also will want to upgrade to a Hydroboost brake booster, so you can actually /stop/. If you've got great trailer brakes, sure, you can use those exclusively... but I wouldn't drive that much without the ability to stop things(even slowly) with the truck brakes.

 

Never thought about it that way, I just knew you had to expand the current holes. Pretty sure I saw a picture a while back of one that was modified, just wasn't right to me I guess. If it was just a beater maybe but this truck will be mine forever and basically new in a few years (rebuilt front/rear axles, rebuilt motor, new floor pan, rebuilt trans, obs interior swap, etc.). I want things to be like factory.

Yeah I know 30k is heavy, I grossed 20k or a little more with the current setup and it was pretty slow. I'll have 4.10s, wide ratio trans and a fresh 7.3 with a r&d 110, stage 1 injectors, good turbo, good intercooler, studs, cam, custom piping. Won't be a record breaker but maybe 300hp to the wheels. Hell of a lot better than the 100 I've got now!

 

I learned interesting information today. ZF S5-42 is widely used in Europe in trucks, and the specs for oil is this: First fill up 75W-80, next fill up 75W-90, next fill up 85W-90, that is what the specs say for DAF company, Mercedes and others.

 

Found this the other day, looks like a great resource.


http://www.zf.com/media/media/docume...ce_manual_.pdf


In this particular document it notes many times all throughout to use Mercon ATF. It also is very specific that trucks with diesel engines should use synthetic fluid, for what it worth.


Personally my truck had gear oil in it when I bought it, I'm am not sure exactly what kind, and it shifted terribly. I drained it and filled it with ATF and it works much better. Even with the gear oil in it the transmission was terribly noisy and I wouldn't say it got any noisier with the ATF.


I would be interested in trying some of the new fluids out there but with the cost it's really something I want to do and find out it doesn't work for me.


Just my .02$.

 

Changed the tranny fluid today, droped 4 liters of 75w-80 in it, shifts with one finger, no gear rollover, I am happy so far.

 

But it will destroy the trans!! Jk, thumbs up and noted for my zf.

 

It should not, it is the zf specification here in Europe, first fillup with 75w-80, next 75w-90, and slightly thicker every change. They do not use atf in it here.

 

"Jk" there is an acronym for "just kidding", Jan.
Could be JK, jk, J/K, J/k, or so on.

Glad to hear yours shifts so smoothly!! What a dream that must be