Well after my 5.12 swap I thought I was good to go tracker was going across desert no problem. it was doing it with rear wheel only I found out. got stuck in sand and only rear wheels sank or turned. the shop that did swap swapped 5.12 ring and pinion into my 01 front carrier and because 4x4 light came on and I was not getting stuck I thought it was working. need to take it back and see what they say

if they put the stock cv shaft on and not the Suzuki sport 96-98 shaft would this cause my 4x4 not to engage but light would still come on?

if they put the stock cv shaft on and not the Suzuki sport 96-98 shaft would this cause my 4x4 not to engage but light would still come on?

I would expect the stock 96-98 shaft would slip out of the carrier, not giving you any front wheel drive.  Only one has to slip out for this to happen.
With it in 4x jack up one side and see if you can rotate your tire (on that side), make sure that CV is rotating with tire.  The one that rotates is not connected to third. 

I will try that ,also if they put the SOTF unit in wrong it wont lock up. its frustrating because they were supposed to just swap the third which would have eliminated the SOTF. But they thought the SOTF was a locker,plus by taking my 4.88 thirds apart and putting the 5.12 gears on them I had no complete thirds to sell

did they put locking hubs on?

I already had the hubs

I have to go back to the parts catalogs lists.  Rock Auto reflects the SAME CVs for both the Sport and the Tracker trucks.

Empire brand (new) LEFT side CV, part #805822 (for both model year trucks)
Empire brand (new) RIGHT side CV, part #805821 (for both model year trucks)
Surtrack brand  RIGHT side CV, part # SK8020 (for both model trucks)

Beyond the air actuator in the 2nd gen diff, there is a difference in the width (to the side gears) between these two differential.  That's why the inner axle shafts are of different lengths.

The difference, I maintain, is with the inner axle shaft.  The 1st gen trucks had an inner axle shaft that was about 3/8ths of an inch shorter than the stock inner axle shaft of the 2nd gen trucks. 

Therefore, IF they simply mounted your 5.12 gears onto your 2nd gen carrier, I think the problem you are experiencing is with the INNER axle shaft is too short now and may be pulling out of the side gear of the 2nd gen differential.

IF they had installed the complete 1st gen diff into your truck, then the inner axle would be of the correct length and you wouldn't be experiencing this issue.

So the EASY fix, I believe, is to drop your front axle housing, knock out the inner axle shaft that came with the 1st gen set-up, then replace it with the original inner axle, which will be 3/8ths inch longer.

OR... have them pull your front diff and, pull the ring gears off the 1st gen diff and have them set it back up the way you intended on the 1st gen diff carrier and retain the shorter inner axle shaft that came on the 1st gen trucks.  This route would be more expensive.

You could pull the front diff, knock out the shorter inner axle shaft, pop in the new one and re-install the entire carrier in your drive way in about 2-3 hours of relatively slow work.  That's IF your back is back into shape, captwoody.  If your back is still giving you grief, then for sure, I'd have a shop do the work.  I'd recommend having a second set of hands, even if your back was recouped 100%.  The assembly is still heavy and awkward to remove.

That's my thoughts and I'm sticking to them.  If your dash light comes on, then you at least have a solid air pressure in your actuator (no air leaks).  They would not have had to completely disassemble your 2nd gen diff to install the 5.12 gears.  They would have had to pull a side gear, unbolt the air actuator, then unbolt the ring gear and slide it off.  Then slide the 5.12 ring gear on, bolt it down and reassemble diff and set the ring gear lash. Installing the pinion gear wouldn't involve disturbing the diff assembly any more than described above.  Chances are pretty good they didn't screw up your front diff assembly and it is fine.

In the pic below, 1st gen inner axle on left, 2nd gen inner axle on the right. 

Beyond the air actuator in the 2nd gen diff, there is a difference in the width (to the side gears) between these two differential.  That's why the inner axle shafts are of different lengths.

The difference, I maintain, is with the inner axle shaft.  The 1st gen trucks had an inner axle shaft that was about 3/8ths of an inch shorter than the stock inner axle shaft of the 2nd gen trucks.

No personal experience as I've yet to deal with my free wheel clutch, but I believe the reason for the different length inner axle is to compensate for the space occupied by the air actuator - the diff assembly is narrower. 

Therefore, IF they simply mounted your 5.12 gears onto your 2nd gen carrier, I think the problem you are experiencing is with the INNER axle shaft is too short now and may be pulling out of the side gear of the 2nd gen differential.

Just swapping the ring & pinion over should not make a difference to the length of the axle shaft required - you would still be using the original free wheel diff center, and the original longer inner axle shaft should still work.

I recall correctly, one of the steps in this "modification" (SOTF delete) involves plugging the air line from the pump module with a golf tee, if this was done, then there is no air to engage the freewheel clutch, which we have been told was re-installed - was that the only mistake?  Right now we're just guessing - what is needed is an examination and assessment.

When I got stuck in the sand my spotters told me my front was not spinning just my rears. Today I put a floor jack under my rear axle and raised it off the ground. locked hubs put in 4x4 and put in gear. The front wheels pulled me forward so I am guessing I have an air leak to diff that when front diff gets hot air line leaks and front wont engage. Or  axle pulling out and then back in may also be a possibility since I did come down a big dune with wheels turned. It is working now so I will check rubber lines to diff

If you had experienced an air leak, your dash light would have been flashing.  You either have an air leak in your diff system... or you don't.   It doesn't come and go.  I don't think you do. 

I still think it has to do with the shorter inner axle shaft installed into the 2nd gen diff.  The thing that puzzles me is the inner axle shaft shouldn't flex, as in, pull in and out of the housing, unless the c-clip isn't on the axle end stub.  I suppose it could then float in and out a bit with suspension flex. EDIT: Just caught myself: the 1st gen axle shaft is 3/8th inch shorter so it COULDN'T lock into the side gear as the first gen inner axle would, so it would be a floater and not locked in. It can't lock into the diff side gear because it is too short.

The splines on the inner axle and the CVs don't fully extend into the side gears.  You can see this by the wear pattern on the CV stubs when they are pulled out.  You can see this by looking closely at the pic I posted above of the two inner axles.  The side gears just grip about an inch of spline on the axles or CV.  So if the inner axle is too short to start with, say it extends only a 1/2" into the driver's side side gear AND it can't lock into the side gear because the C-clip isn't near the edge of the side gear, so when extended the CV axle pulled the inner axle outward enough so it would not engage into the side gear.  That's the only scenario I can imagine for your loss of front wheel traction.

Did you hear any grinding or a buzzing noise when you applied power when you were stuck?  That would have been the splines trying to get back into the side gear.

which side is the inner axle you talking about on the passenger or drivers side. C clip was damaged when they put oil seal and plastic bushing in. thought it was damaged during install of 5.12 gears but is sounding like its pulling in and out

Quote from: nprecon on July 06, 2015, 08:31:57 PM

Beyond the air actuator in the 2nd gen diff, there is a difference in the width (to the side gears) between these two differential.  That's why the inner axle shafts are of different lengths.

The difference, I maintain, is with the inner axle shaft.  The 1st gen trucks had an inner axle shaft that was about 3/8ths of an inch shorter than the stock inner axle shaft of the 2nd gen trucks.

No personal experience as I've yet to deal with my free wheel clutch, but I believe the reason for the different length inner axle is to compensate for the space occupied by the air actuator - the diff assembly is narrower. 

Quote

Therefore, IF they simply mounted your 5.12 gears onto your 2nd gen carrier, I think the problem you are experiencing is with the INNER axle shaft is too short now and may be pulling out of the side gear of the 2nd gen differential.

Just swapping the ring & pinion over should not make a difference to the length of the axle shaft required - you would still be using the original free wheel diff center, and the original longer inner axle shaft should still work.

I recall correctly, one of the steps in this "modification" (SOTF delete) involves plugging the air line from the pump module with a golf tee, if this was done, then there is no air to engage the freewheel clutch, which we have been told was re-installed - was that the only mistake?  Right now we're just guessing - what is needed is an examination and assessment.

Exactly.  I attempted to measure these differences when I had the two diffs laying out on my garage floor a couple months ago, but I found it impossible to hold the tape and get a quality picture.  I needed three hands.  I wanted to quantify the differences.

The inner axle is the short shaft on the driver's side that extends into the axle housing and that the driver's side CV bolts to with the three bolt flange.  The inner axles are pictured above in this thread.  The 1st gen inner axles are 3/8ths inch shorter then the 2nd gen inner axles BECAUSE of the differences in the diff design width. 

which side is the inner axle you talking about on the passenger or drivers side. C clip was damaged when they put oil seal and plastic bushing in. thought it was damaged during install of 5.12 gears but is sounding like its pulling in and out

What do you mean by "C clip was damaged"?  Did it break?  Did they replace it?

When I got stuck in the sand my spotters told me my front was not spinning just my rears.

What is the possibility that the spotter could only see one front wheel?  With an open diff in front, if one wheel has no traction it will spin, and the other one will not.