Hello all. Wondering what's involved in changing from 4.10 to 3.55 in a sterling 10.25" rear axle.

I would love to hear from your experiences.

 

Not to hard really I swapped out a 3.55 to a 4.10 in a truck 2 months ago so it's real fresh. 1st and foremost check to see if your wheel seals are leaking if so the process is more complicated. Assuming no leaks jack up the rear end or if you have a lift even better. Get the wheels off the ground leave the wheels on less parts laying around that way. Un hook your drive shaft. Pull the rear cover there is almost 4 quarts in there so a good size pan is advisable. Remove the 8 small bolts on each side pull the axle out about 4 to 5 inches leave it there throw a clean rag over the top of it on each side. Remove the 4 bolts that hold the ring gear assembly into the housing be careful it is a little heavy watch how the spacers come out as it needs to go back in the same way. Get the ring gear assembly nice and clean much nicer to work on. Next is the pinion shaft removed the large nut on the driveshaft side the pinion will come right out get a new pinion shaft seal good time to replace it. If your going to use the original pinion bearing check for pitting this bearing is also pressed on with spacers. You will need a micrometer to get the proper spacing which is important you don't want to much load on the edge of the pinion gear. Removing the ring gear is easy and the new one will need to be torqued back on at around 110 ft lbs per bolt. Everything from this point on needs to be torqued. Assemble reverse order. The ring and pinion are matched sets. Have fun!

 

You will also have to pop each axle out at the wheel hubs.
Its also a good idea to use a marker ink on the gears after everything is setup to see how they are actually tracking.

I went from 4.10 gears to 3.08 gears with my 86 diesel, made a world of difference.

 

Thanks for the info. Doesn't seem that it will be too tough.

All the best! Evan

 

I have a '84 F250 that I want to change to 3.08, but it is a 4x4 is there a significant difference in prceedures for swapping the gears on the front axle? And while I have it apart how much more would it take to install limited slip to both? And what does "full cluster 3.08LS" mean?

Thanks for any experienced advice!

 

Dismantling the front differential is a little more involving than the rear, but the same basic proccedure applies.

You will have to check to see what type of front end you have, since the D50 was not offered with a 3.08 ratio, and I found out during my research that no one makes an aftermarket set. The lighter duty D44 front does have an avalable 3.08 ratio.

If your truck has a manual 4 speed tranny, than it may be worth swapping to a 5 speed tranny. It will be about as much trouble as swapping both gear sets, and cost similar (no promises), but drivability will be better.

As for my cluttered signature, thats what happens when you have a limited number of characters to work with, it never does quite look right (but I am trying).

Full cluster reffers to my factory gauges: optional trip meter, and tachometer. The "LS" behind 3.08 means limited slip.

 

Initailly I wanted to trade in my T19 for a 5-speed..but I was getting some pretty involved and rather expensive change over estimates.

So I was thinking that for now changing the gearing would be the quickest and least expensive solution, and I really want LS in both axles. Then possibly later down the road investing in a gearvendors unit for $2800. (I bought the truck for $1300) Maybe I will get lucky and find a 3.55 gear 4x4 set out of a F350 at PickNPull. I was thinking 3.08 would be great since I am mostly on the freeway...but if they don't have that ratio for the front end then 3.55 will be better than what I have and eventually trade in the T19 for a 5speed or a gearvendors unit. I just need to get the ratio up quick so I can keep up with traffic without the engine overheating! I have to keep my speed down and stay in the slow lane to prevent the temp from climbing.

 

"I have to keep my speed down and stay in the slow lane to prevent the temp from climbing."

I would get your cooling problems fixed first. You have a serious problem if you are overheating in normal city traffic.

Unlike a gas motor, a diesel will cooler at light throttle, heavy traffic, stop n go, idle speeds. Unloaded and just keeping up with traffic should not cause a heat problem.

Likely your radiator is getting a bit plugged up. Could be thermostat or fan. If you are already having trouble with heat, a higher gear ratio may run even hotter.

 

Mine had a tendancy to run hot at higher rpm (over 2500) as well, so I reclpced the thermostat and haven't had any problems since. Go directly to ford or international if you get a replecement Tstat, aftermarkets never work properly, I nearly learned that the hard way......

If you want to start making upgrades to keep up with the newer trucks, than market value goes out the window. I apent $3500 CAD for my truck and have spent about that much in upgrades in the two years I've had it, but its been worth every penny.

For the high rpms, I would keep an eye out for what you can find in the way of gears or a 5speed. where I am, the cost of two gear sets cost about the same as a tranny, but it depends on the stiuation. I have heard of some who have picked up a zf 5speed for anywhere from $600 to as little as $150! Swapping the trans is heavier, but overall, less trouble since you don't have to worry about lining up any gears. Good luck with whatever you decide.

 

Thanks. I will check on gettin a thermostat monday from the ford dealer. It runs normal temp around town and even with a load, which is why I wasn't thinking the thermostat was the problem. The only time it starts to climb is when she runs at excessively high RPM for extended time (ie above 65 mph).

I don't mind putting in another $1500 or so each year. I plan on keeping her for years to come. When I checked on ZF5 I couldn't find anything under $1500 plus and I would need a new clutch for ~$400 more, and there are a few modifications that have to be made for it to fit the 4x4, but if I found one for under $500 I would be doing it now. It seemed it would be quicker to change the ring & pinion just to get the RPMs down out of the red zone on the Freeway, (I plan to do both eventually).

 

Me too, I may have 3.08 gears, but I'm still putting an E4OD in (waiting on parts right now).