Anyone have a link or can provide some differences between the front gears installation and the rear installation?

I've done several rear gear installs, none on the IFS. This is for a 93 GMC. Also, does anyone have a good cheap place for the front and rear gears, 4.88 is what I'm looking for.

I tried the FAQ and searched a bit, and didn't find what I was looking for.

Why are you wanting to put 4.88's in the IFS? If you're doing it so you can spin the big meats you have you're going to be disappointed. Tires large enough to require 4.88's are too large for IFS and I'd hate to see you sink all the money into the swap when the whole system is subpar. That said I will see if I can get some pages from the manuals for you tomorrow.

Why are you wanting to put 4.88's in the IFS? If you're doing it so you can spin the big meats you have you're going to be disappointed. Tires large enough to require 4.88's are too large for IFS and I'd hate to see you sink all the money into the swap when the whole system is subpar. That said I will see if I can get some pages from the manuals for you tomorrow.

Thanks, I have 38's with 6" of suspension and 3" body lift. I can't seem to find any suggestions anywhere.

The truck doesn't have much pickup at all. I've been out of the truck game a while, but I had a 78 with a small cam and it would bake the 38's in 4wd and this 93 doesn't even seem to want to move. I assumed it was the gears since I got the motor running good.

Thanks, I have 38's with 6" of suspension and 3" body lift. I can't seem to find any suggestions anywhere.

The truck doesn't have much pickup at all. I've been out of the truck game a while, but I had a 78 with a small cam and it would bake the 38's in 4wd and this 93 doesn't even seem to want to move. I assumed it was the gears since I got the motor running good.

you know what gears you have in there? the problem with going to that gear is your going to make the teeth really small and probably blow the thing up the first time. all the cool kids are putting solid front axles under their trucks

38's + IFS= :nuke:

If the experience doesn't have those pages handy, I think I have a copy.

The two big differences are since you split the case open, 1. the carrier bearing preload is set by threaded adjusters that take a special spanner and 2. since you can't get inside the case to measure backlash, measure at the driveshaft yoke and divide by 2.

But...if you are going to polish the turd, go ahead and start saving some $$ to replace all those broken parts.

Then swap in a solid axle. You'll be time and money ahead.

38's + IFS= :nuke:

If the experience doesn't have those pages handy, I think I have a copy.

The two big differences are since you split the case open, 1. the carrier bearing preload is set by threaded adjusters that take a special spanner and 2. since you can't get inside the case to measure backlash, measure at the driveshaft yoke and divide by 2.

But...if you are going to polish the turd, go ahead and start saving some $$ to replace all those broken parts.

Then swap in a solid axle. You'll be time and money ahead.


So basically there isn't even a point in messing with either the front or rear axles, the gains from putting in the gears would be minimal compared to the heartache the wallet feels? I'm also going to assume that everyone feels the same way about the 8.5" rear. The gears in it now are stock, whatever those are.

Am I the only one that thinks these TB motors are turds in these trucks? The motor runs good, no leaks, with 110k miles. The truck has absolutely no pickup. I bought the truck with the lift on it already. I just seen that one of the rear stock springs was cracked so I ordered a new set of 6" lift springs so I could get rid of the blocks. Sorry for that tangent, my question related to this is, since I purchased the truck with the lift and tires on it already, how would I know if it has been calibrated to reflect for the larger tires. And a better question, how are these corrected for that? I have a 98 Camaro which I have HP Tuners for and changes in the speedo for that are simple. I'm guessing this being much older requires a different approach.

So I will be able to sell that IFS lift kit for a pretty penny and be able to probably buy a decent front axle and be somewhat on my way. Are there any links for the conversion, because I'm sure there is more to it than just taking out the IFS and just plopping in a solid 12 bolt axle with some 6" lift springs for the front. I don't recall seeing any mounts for the springs, I assume that would have to be fabricated.

Thanks for the insight and sorry for the length background/questionnaire

The TBI engines are fine, I like mine. It has enough power to get the job done, but not enough to be constantly breaking u-joints, axle shafts, transmissions, etc.

As for the IFS gears, I too will tell you that putting ANY money into those axles is stupid. Even more so running 38's. I managed to grenade my 8.5" 10-bolt with stock tires on pavement, it doesn't take much for them to give up the ghost.

if your not planning on wheeling it, the axles will be fine the ten bolt would be my concern more than the front. we can hook you up on gears, but i would find at least the 12 bolt for the rear if not a semifloat 14 bolt or full float.

I have that same motor in my 89 with 4:56 gears and it has plenty of pickup. In my opinion, even if you aren't going to wheel it, I would at least go semi float 14 bolt in the rear and a D44 front. You could find those cheap and probably with 4:56 gears already. Then you are good and strong even for light wheelin. If you are going to wheel, do the ff14 and D60. You won't have to upgrade from that.

I have that same motor in my 89 with 4:56 gears and it has plenty of pickup. In my opinion, even if you aren't going to wheel it, I would at least go semi float 14 bolt in the rear and a D44 front. You could find those cheap and probably with 4:56 gears already. Then you are good and strong even for light wheelin. If you are going to wheel, do the ff14 and D60. You won't have to upgrade from that.

I'd like to use the truck for some fun. It's a DD, but I'd still like to take it into the mud and have fun. Is there a kit that is used for converting the IFS to solid axle?

Also what about the correcting the speedo question?

IFS and 38's big problems man, and no don't even bother with a D44 thats no better. ff14 and D60 is the way to go man.:grinpimp:

The gears in it now are stock, whatever those are...Am I the only one that thinks these TB motors are turds in these trucks? The motor runs good, no leaks, with 110k miles. The truck has absolutely no pickup.

Stock gears + 38's and you wonder why it's a turd? It's not your engine, it the big ass tires and stock gear ratio.

I doubt you'll get much for a used lift kit.

I'd like to use the truck for some fun. It's a DD, but I'd still like to take it into the mud and have fun. Is there a kit that is used for converting the IFS to solid axle?

Search for SAS threads. ORU has a $$$ kit, Sky mfg, or make it yourself.

Also what about the correcting the speedo question?

Probably hasn't been corrected. GPS is the easiest way to check. Or check mileage/vs time on the interstate. Set cruise to 60mph. should take 1 min to go 1 mile.

435693

435694

The speedo is about 8 mph off at 55 mph, I used a GPS to confirm that.

There are alot of mixed opinions in here, I think that I'm just going to find some gears and throw them in there and hope for the best. I spoke to my wife's uncle and he's had his 4.56 gears in his 97 Suburban for over 200,000 miles with plenty of muddin in the equation. He has 36's so I think I'm just going to take my chances with the gears. The motor isn't making any great amount of power, probably 175hp if I'm lucky.

This leads me back to my original question, anyone have a link for the IFS gear installation?

Bumpage

There really isn't a good write up that I know of. In a nutshell, here is how it works:

1. Remove front diff from truck.
2. Use a length of 2x4 and a hammer and knock the CV flanges out of both ends.
3. Remove the 5 15mm bolts that hold the long side to the main chunk.
4. Remove the 10 15mm bolts that hold the two halves of the main case together.
5. Using a mallet or hammer and wood, remove the carrier adjusters to replace the metal locking tabs (GM Part # 15588312).
6. Re-install the adjusters with new locking tabs in place.
7. With the new gears in place, put the two halves of the case back together.
8. Using a D44 spindle nut tool, adjust the backlash. BL = Yoke measurement/2.
9. Remove the large plastic breather hose cap to paint the gears to check the pattern.

FYI the 8.25 IFS unit uses the same pinion bearings as the 10B.

Lastly the 5.7L TBI motor is a good motor when the gearing is correct.

There really isn't a good write up that I know of. In a nutshell, here is how it works:

1. Remove front diff from truck.
2. Use a length of 2x4 and a hammer and knock the CV flanges out of both ends.
3. Remove the 5 15mm bolts that hold the long side to the main chunk.
4. Remove the 10 15mm bolts that hold the two halves of the main case together.
5. Using a mallet or hammer and wood, remove the carrier adjusters to replace the metal locking tabs (GM Part # 15588312).
6. Re-install the adjusters with new locking tabs in place.
7. With the new gears in place, put the two halves of the case back together.
8. Using a D44 spindle nut tool, adjust the backlash. BL = Yoke measurement/2.
9. Remove the large plastic breather hose cap to paint the gears to check the pattern.

FYI the 8.25 IFS unit uses the same pinion bearings as the 10B.

Lastly the 5.7L TBI motor is a good motor when the gearing is correct.

Thanks!

I've got the ol 5.0 TBI though.

Yeah, that pretty much sums it up. Sorry, I looked around to see if I could find my copy, but it's been a few years since I did the gear swap.

When I did mine, I went to the chevy stealership and asked one of the guys in the service department if I could make a copy of a few pages out of his service manual. That's worth a shot. That way you'll get the correct torque specs and what not.