Converting M1009 front differential to Pos--trac style

[Blood_of_Tyrants]

So, I'm looking to replace the open differential in the front axle of my M1009 with a limited slip differential and have a few questions. Seems to be a fairly cheap mod with used diffs going for $100 or so.

First, how many splines does the front axle shaft have?

Second, can I reuse the stock 3.08 gears (assuming they aren't shot)?

Third, I have heard that you don't use standard gear lube for a limited slip differential. is this true? If so, what is the proper lubricant? Do I need to clean the axle housing and get the gear lube out?

Fourth, do I need to reset the gear lash? (I wouldn't think so as long as I use the same thickness gasket on the differential housing.)

Fifth, do I need to make sure that the 3.08 gears will fit or are ring gears a universal fit?

Sixth, what do I need to make sure is included except for gaskets and seals?

Seventh, are there any brands to avoid?

Last, is there anything particular that is a warning flag when buying a used limited slip diff?

 

[FireFighterHill]

Some Limited slip differential require a friction modifier. Some gear lubes include the fluid already some dont.

 

[Blood_of_Tyrants]

Got to be more answers out there.

 

[FireFighterHill]

From what I can find. Any fluid that says on the bottle that it is compatible with limited slip diff or LSD compatible should be fine.

 

[rlwm211]

Hi; Regarding questions 1,2,4,5

I believe the front diff on the 1009 is a dana 44.
Summit also has a identification chart to help to verify which front end you have.

You can use a new carrier with your old gears provided the carrier is designed to use the gears you have. gear depth is the issue and some carriers have deeper shoulders than others. depending on the ratio.

If you can use your gears over, the only thing you need to is set the lash of the pinion gear and the center carrier. That would require you use paint of some other marking agent to identify where the gears are meshing to make sure you have the carrier in the right location left and right and that there is not too much slop in the mesh.

Question 3; The additive for limited slip is cheap and you only need about 5 or 6 ounces added to the normal gear oil. The lube should be available at any auto supply. I would go by the recommendations of the posi, or limited slip manufacturer.

Question 6 You can get an "installation Kit" from a place like summit racing for about 40 bucks. That would include new bearings, shims and a crush collar for setting the pinion depth if you have to redo that. That should not be necessary. Hopefully you would install the old ring gear on the new carrier after pressing on the bearings and then install it in the differential and set the lash. You will need the new bearings as the fact is you would most likely ruin the old bearings trying to remove them from the center carrier to use them on the new carrier so I would plan on buying the kit with the bearings anyways. There are good manuals available for the "blazer" type vehicle and they have a good procedure for setting up differentials in them. Last time I used a Chilton's manual. It does not matter once you have the specs for your vehicle and if ytou PM me, I can look them up for you in the software I have.

The gasket is included as far as I know.

I have not done a differential in 5 years so I am a little foggy on all the parts and pieces. Still, if you follow the proceedure it is not hard to do and it can be done in the vehicle easily as long as you have adequate room to move around under the rig and it is properly supported while you work on it.

Hope this helps

RL

 

[Blood_of_Tyrants]

The specs say that both axles are GM corporate axles.

 

[4bogginchevys]

So, I'm looking to replace the open differential in the front axle of my M1009 with a limited slip differential and have a few questions. Seems to be a fairly cheap mod with used diffs going for $100 or so.

First, how many splines does the front axle shaft have?

Second, can I reuse the stock 3.08 gears (assuming they aren't shot)?

Third, I have heard that you don't use standard gear lube for a limited slip differential. is this true? If so, what is the proper lubricant? Do I need to clean the axle housing and get the gear lube out?

Fourth, do I need to reset the gear lash? (I wouldn't think so as long as I use the same thickness gasket on the differential housing.)

Fifth, do I need to make sure that the 3.08 gears will fit or are ring gears a universal fit?

Sixth, what do I need to make sure is included except for gaskets and seals?

Seventh, are there any brands to avoid?

Last, is there anything particular that is a warning flag when buying a used limited slip diff?

#1.....28 splines, dana 44 is 30 and is wrong

#2.....Make sure the corporate carrier you get is for 3.73 and down

#3......use any 70-80-90 you want, limited slip additive prevents "chatter" of the clutches with-in the case, I have gone without using the additive many times on a diff flush without issue, but if you put it in you get piece of mind. Nearly any additive will work, look for "limited slip" on the label and you should be fine.

#4....you need to reset lash...not that hard but a bearing puller will make it alot easier. I would re-use the old bearings if good or you may have to reset pinion depth aswell. If you do not loosen the pinion nut than you do not need a new crush collar, if you loosen it, you do.

#5....universal to "corporate"

#6.....if your not buying it as a kit, dont get anything yet....many times i've set up gears and generally speaking I was able to use shims that were already on the other carrier, move them side to side, or even leave one out, your choice now or later.

#7....I dont know of any to avoid specifically in a stock 1/2 ton truck install.

#8....look for all necassary "keepers" to be installed retaining the clutches, it would be best to take a set of axles and check the "break away" of the clutches...there should be a fair amount of tension on the spider gears and the end gears should not be turned easily ( this is the posi action ). Look for cracks in the spider gears, and if the center pin has ever been broken and walked around in the housing you will see denting of the carrier, be very careful with this, sometimes the strength of the carrier has been comprimised. It's also a good idea to have the axles with you to check the fit of the splines in the end gears...just keeps everyone honest and some poeple dont even know what thier selling.

#8....good luck

 

[Blood_of_Tyrants]

Thanks for all the info. From what I have read in the TM, the only adjustments I have to worry about is the gear lash to get the carrier centered.

 

[scrambled]

I have used Auburn limited slips in the front before. It is a great setup. I would not buy a used one because they cannot be rebuilt, and someone may have run it without additive.

have you thought about a "lunchbox" locker like an EZ or Aussie? I have used these in the front of blazers before. they work great offroad and you can still overpower them in a tight turn. They are also much easier to install as no carrier change is needed.

 

[4x4 Forever]

Depends on how much you want to spend, did notice the $100 thing though.

ARB makes a good set up, if you wanted to go that route. This would allow you to use locker in the front only when you wanted or needed to.

http://arb.com.au/resources/pdf/airLockers/application_chart.pdf

 

[Blood_of_Tyrants]

I have used Auburn limited slips in the front before. It is a great setup. I would not buy a used one because they cannot be rebuilt, and someone may have run it without additive.

have you thought about a "lunchbox" locker like an EZ or Aussie? I have used these in the front of blazers before. they work great offroad and you can still overpower them in a tight turn. They are also much easier to install as no carrier change is needed.

Interested. Can you post more info?

 

[porkysplace]

its usually a good time to spend a few extra dollars and replace the u-joints on the axels and save trouble later

 

[scrambled]

Here is link to an install article.
Jeepin.com: Detroit's EZ Locker

you basically remove the spider gears in the carrier and install the locker. The locker uses springs to hold the side gears against each other. This will transfer power to both wheels. Since the springs are not that big, you can unlock it in a turn with a little power. You only have to remove the diff cover to do the install.

These lockers go for around 300 bucks. I have used Lock Rites which are now called Powertrax Lock Right. I used them in both axles of my scrambler for 3 years of wheeling Tellico and in the front of my Blazer for 2 years. I never broke an axle and the added traction was great.

I have replaced one of these years ago for a guy. he liked doing burnouts on blacktop and eventually wore the gears down to nothing. Other than that, I never saw a problem with them.

 

[Blood_of_Tyrants]

I don't think I'll be doing many burnouts in a CUCV with a 6.2L diesel engine.

Also, can I do it without removing the carrier? It looks like a booger getting the carrier shims back in.

 

[bronconut]

veary simple to install a lockright or ez locker just remove axle shafts, bolt holding cross shaft , cross shaft and all spider gears than install locker. no need to remove carrier as 308 gears are large enough to allow you to fit the locker in with out having to remove it. simple and reliable cant go wrong

 

[Blood_of_Tyrants]

Thanks, with the surprise bonus check I just got from a previous job , I'm going to do it as soon as the weather warms up.

 

[kassim503]

You wont be able to do the job with the carrier in the housing, or at least reasonably. Honestly its not that hard to jam a lunchbox locker if your using the same carrier, you dont need any special tools despite what proper methods say. Removing the carrier goes like - remove wheels, rotor, spindle, axle shafts, cover, main bearing bolts (4), make sure you put a nice soft mat for the carrier to land on and chain up the carrier and yank it out with the chain tied to your vehicle of choice. Easy as cake right? (not)

To ram the carrier back in, if your reusing the carrier and spacers, tap on the carrier using your favorite mallet, until you can thread the bearing caps and use those to cram the carrier back into the case and reverse steps to reassemble. No axle spreader needed!

 

[LionsLegacy]

I had my M1009 stuck int he snow the other day, and even though I had both axles locked out, The wheels weren't spinning equally, and I guesses that maybe I already HAD limited slip/posi trac style. Should I be worried ?

 

[AJMBLAZER]

Hey, Traverse City...

When you say they weren't spinning equally do you mean front vs rear or side to side?

 

[4bogginchevys]

I had my M1009 stuck int he snow the other day, and even though I had both axles locked out, The wheels weren't spinning equally, and I guesses that maybe I already HAD limited slip/posi trac style. Should I be worried ?

That diff is OPEN, if they spun at the same speed it would be very difficult to turn in 4wd....is it? Doesn't sound like a problem from here....