Sad news and a Question

[tmcalavy]

Well, got some sad/bad news from a trusted mechanic yesterday. He put my 93 Ranger supercab XLT up on the lift to find the source of the howling in my differential. Said all the bearings are making noise...not what I wanted to hear. I towed the Ranger 800+ miles behind a big Pennske truck when we moved from Texas to Miss. about 2 months ago...been making the howling noise ever since I took it off the tow dolly. Had the driveshaft off and tied up, and I changed the lube, put in some additive, and changed the driveshaft support bearing since then...hoping this would stop the noise. Mech thinks the diff bearings simply overheated on the trip since the truck was at an angle on the tow dolly and that it couldn't circulate the lube around at that angle. That's the back story. Have got a coupla sources for replacement differentials cause replacing the diff entirely will be cheaper than fixing the old howler.
Here's my question...are the spring perches, etc. in the same place on an 8.8-inch Ranger rear end as the perches, etc. on a 7.5-inch rear end? I've read online that it's a straight swap when you replace a 7.5 diff with an 8.8 diff, but thought I'd ask. I have a line on an 8.8-inch diff out of a 2000 Ranger with 4.0 engine and 4WD. Waiting for a call/text telling me what gear ratio it has...mine is 3.45 so I'm hoping it's somewhere near that so it will work with my 3.0 and auto tranny.
Thanks in advance, any input is appreciated.

 

[adsm08]

The 3.0/auto trans doesn't give a flying F about the rear end ratio. I guarantee it won't be 3.45 though.

The swap will be fairly straight forward, but you will need to get a new drive gear to correct the speedometer after the swap. My advice, if it has 3.27 gears pass on it. If it has 3.73s be happy. If it has 4.10 gears grab that bastard get in the truck, and run before the guy can change his mind.

Since you have an auto trans correcting the speedometer quickly will be important.

 

[tmcalavy]

You're right...hadn't thought about the speedo gear until now. Just hoping to confirm that is a bolt in swap, since the donor truck was 4WD and mine is just 2WD...been bitten before by differences in spring perches, etc.

 

[Mac]

The 3.0/auto trans doesn't give a flying F about the rear end ratio. I guarantee it won't be 3.45 though.

Direct swap in but couldn't it be a 3.45 ratio? I sure wouldn't want one again.
Dave

 

[adsm08]

Direct swap in but couldn't it be a 3.45 ratio? I sure wouldn't want one again.
Dave

8.8 was not offered in a 3.45 ratio. So no, if he is truly looking at an 8.8, it will not have 3.45 gears.

 

[Mac]

8.8 was not offered in a 3.45 ratio. So no, if he is truly looking at an 8.8, it will not have 3.45 gears.

The OP was asking if the 8.8 was a direct swap for a 7.5. Am aware that he can't match the gear he has. Not sure I buy that about truck being on angle not allowing lube to circulate.
Dave

 

[Andy D]

Yah, if the diff was a bit low, I could see the angle putting the lube in the cover , not the ring gear. Make sure the lube is full, and it can howl for sometime. Take your time , do some research and get the rear end you want. My 4.0 Rat has 3.27 gears. I 'm running 235 15s and find the gears just great. At 65 mph the engine is only turning 2000 RPM. I'm just going for a cheep light duty 4wd PU . Had me my druther's I wish it had a 3.56 posi in back and open in front. BTW, I'm fine with 10" drums out back.

 

[tmcalavy]

Yeah, wasn't sure about the projected cause myself but he says the roaring is all over the diff. It had what I call half a load on it, pretty full bed, and it went 800+ miles behind the big truck so I guess I'm lucky it didn't crater on the road. New job means I'm short on cash, so a used diff and diff swap is the cheapest option if I can find a good used diff. Until then, I can live with the howling...just drive it work and back, bout 12 miles a day.

 

[adsm08]

The OP was asking if the 8.8 was a direct swap for a 7.5. Am aware that he can't match the gear he has. Not sure I buy that about truck being on angle not allowing lube to circulate.
Dave

I dunno, I'm confused now. I thought you were asking me how I could be sure that it wouldn't have 3.45 gears.

My 4.0 Rat has 3.27 gears. I 'm running 235 15s and find the gears just great. At 65 mph the engine is only turning 2000 RPM.

And that is great for a 4.0. He has a 3.0 which likes to rev up.

 

[tmcalavy]

Thanks for the encouraging words. The guy with the 8.8 diff is dragging his heels, but I've found a 7.5 with 3.73 ratio and 9-inch brakes that I need to look at too. I know my truck (XLT) has 10-inch brakes, but don't think the smaller brakes will matter much...I'm an old coot and drive like one.
Is a lift essential for swapping differentials? I can get the swap done for about $175, but am wondering if I can do it myself. I have jackstands, a good hydraulic floor jack and an electric wratchet gun plus sockets. Anyone have any experience swapping a diff from ground level?....do-able or not? Any input is appreciated.

 

[PanamaExpat]

Is very doable. I would drop the whole rear end springs and all and put new spring eye and shackle bushings in while you have it apart. They are not that expensive. Be careful removing the brake lines as they tend to be corroded into the wheel cylinders. Unhitching the e-brake cable is a bit of rectal pain you will also need to use some caution when unbolting the sway bar. I sheared off a couple bolts when I dropped mine. Another hot tip is remove the bed. It is six bolts and a couple small screws on the filler neck then two people to lift it and carry it off to the side. Makes it much easier to get to everything on the rear axle if the bed is off. Should take you about a weekend and two cases of beer to do it all up. Also remember if you run into problems you have us.

 

[85_Ranger4x4]

Yah, if the diff was a bit low, I could see the angle putting the lube in the cover , not the ring gear. Make sure the lube is full, and it can howl for sometime. Take your time , do some research and get the rear end you want. My 4.0 Rat has 3.27 gears. I 'm running 235 15s and find the gears just great. At 65 mph the engine is only turning 2000 RPM. I'm just going for a cheep light duty 4wd PU . Had me my druther's I wish it had a 3.56 posi in back and open in front. BTW, I'm fine with 10" drums out back.

IMO if it was that low its days were numbered anyway.

My parent's Explorer had 3.27's, absolutely worthless. It couldn't hold a gear to save its life, just too much gear in the axles for the just adaquate 4.0 to maintain speed. It had the stock 235/75-15 AS tires too. Very stupid move on Ford's part to even think of offering that kind of a ratio in most of the country.

Another hot tip is remove the bed. It is six bolts and a couple small screws on the filler neck then two people to lift it and carry it off to the side. Makes it much easier to get to everything on the rear axle if the bed is off. Should take you about a weekend and two cases of beer to do it all up. Also remember if you run into problems you have us.

Somebody doesn't have salt on their roads...

That can be a very long, drawn out and sometimes bloody battle in some parts of the US.

 

[PanamaExpat]

Somebody doesn't have salt on their roads...

That can be a very long, drawn out and sometimes bloody battle in some parts of the US.

I think I must have gotten lucky and my truck was imported from from the Southern USA as I must admit my truck undercarriage isn't nearly as rusty as most of the ones I see on here.

 

[Andy D]

Can you swap the 10 inch brakes onto the new rear end?

 

[mk42gunner]

I'd start spraying all the bolts with your favorite snake oil now, and continue daily until you do the swap. It can't hurt, and might actually help with getting some of the nuts off.

Other than that, the only other thing to remember is to not drop the rearend on your toes or head.

Oh, and get some help to bleed the brakes afterwards.

Robert

p.s. I had a 3.08 geared 8.8 that howled for about 135,000 miles; 90,000 while I owned it the rest after I sold it to a friend. It startred howling after a trip from California to Missouri grossing about 9,000 pounds.

R