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Axle conversion questions

Fifty

Well-Known Member
I have my 18 Colorado ZR2. It has a Dana 44HD, or the m220...Its called both depending on who you talk to. From what I am told by the Diff guy who did my gears, that it seems a pretty stout axle, decent spline count and size shafts etc. But he did say that the weight and leverage of a 35 inch tire and 330 hp/300 tq is its limit. The axle has abs/traction control sensors that mount in the back of the e-brake. As much as I would love to just eliminate that, there is no way to with out the BCM throwing every nanny leash on. The truck has a way to turn the abs/Traction control off, but the truck still needs to monitor that sensor.

Some day, funds permitting, I would like to move up to a 37 inch tire. So my idea was to swap in a ford 9 inch (since parts seem readily available should I link it etc). and graft the ends of the stock axle on it. So it would be a 9 inch from the pumpkin until the brake tab, and then run the brakes (including the abs sensor) from the oem axle. Then I would need to have a pair of axle shafts made that are the correct length, that have the 9 inch inner and the d44hd outer.

Is this an out of the realm idea, am I getting way to cost prohibitive?

I am still trying to find out if the gmc yukons, sierras, silverados use the same abs/traction control pulse number. If they did, I could swap that axle in instead and it would be easier... but it seems short of buying one and counting teeth on the shafts.....
 

partybarge_pilot

Well-Known Member
Get a 9" floater and put a tone ring on the output shaft of the trans.
 

michael.gonzalez

Well-Known Member
Traction control needs 4 wheel speed sensors. 3 won't make it happy.

Unless you can put both sensors on one ring and fool the computer into thinking you never have speed differential from left to right but that may throw some codes.
 

Fifty

Well-Known Member
Traction control needs 4 wheel speed sensors. 3 won't make it happy.

Unless you can put both sensors on one ring and fool the computer into thinking you never have speed differential from left to right but that may throw some codes.
Yep
 

michael.gonzalez

Well-Known Member
Could be worth a try.

Has anybody put a spool in the rear end of a new colorado and gotten error codes/warning lights?

It will essentially send data the same way a spooled rear end would.
 

Fifty

Well-Known Member
Could be worth a try.

Has anybody put a spool in the rear end of a new colorado and gotten error codes/warning lights?

It will essentially send data the same way a spooled rear end would.
You will get a locker error code if it’s a zr2. It has an Eaton e locker.
The regular Colorado has the g80. So no code if you put a spool.
Although if the traction control algorithm doesn’t receive the anticipated G meter response you will start cooking the rear brakes.

I apparently did Not turn my traction control off all of the way on one of my runs and when I serviced my brakes the rear caliper seals showed severe heat damage where as the fronts just showed bad heat damage lol.

but seriously the traction control today uses g meter as well as wheel speed to activate and so much is rear wheel braking.
 

partybarge_pilot

Well-Known Member
Get custom brake hats made with little steel slugs pressed in. Mount pickup in caliper mount.

Edit: if you ran anything that really locked up like a Detroit, wouldn't you get the same errors?
 

jeff

Moderator
Until I see pictures of the truck getting seriously flogged off-road I don't see any pressing need to update the rear end. ;) The rest of the truck will probably break before the rear end gives up the ghost.

Some of the newer Jeeps use a similar M220 that the Colorado V6 and Diesel equipped trucks use. The M220 signifies it has a 220mm ring gear which converted to Merica' means it's an 8.66" ring gear. You might find more information if you search for a Dana 46 instead of the M220. That seems to be the designation a lot of guys have settled on using.

I'm not sure what you are worried about breaking but if it's axles it might just make more sense to upgrade the axles and leave the housing and diff alone. RCV has a $1900 axle upgrade for the M220 (Jeep) that comes with a lifetime warranty for use with up to 40" tires. If that's too expensive there are other axle manufacturers out there that will make you a higher quality axle than what is in there now.

The stock housing could probably use some bracing (Truss?) if you worried the housing itself may "bend" if you are jumping the truck.

Aloha
 
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Fifty

Well-Known Member
Oddly enough the d46hd that the zr2 has uses larger diameter shafts than the jeep. I called RCV to see if there was a way and they said no.
Nitro gears makes a 4.10 and 4.56 gear set now. I swapped gears to the 4.56 before the 4.10 were available. When they shipped the kit, I guess they shipped the jeep or rover version as the bearings and seals were too small. (I didnt do the gears, the rear end shop in livermore did). He mentioned that the pieces for the gm version were a little more stout than the jeep equivelant, and suggested that I stop at 35's. I spent 2 months on the stock 30.5's with the new gears while researching and found 2 trucks on 37's and both grenaded the diff. One was something in the pumpkin and the other was a shaft. So I went with 35's
Id happily* run new rcv shafts as it would definitly be cheaper than this conversion idea that Im concocting. But will the pinion gear be strong enough as well? One wthing for sure, if I go up to 37's, its going to have to be with a supercharger...
It may say 308 hp and I cant remember the tq from the factory and with the small bolt ons and tune showing around 30 dyno whp avg....it neeeeeeeeds more oooomph to push that weight.


*when I say happily, I dont really mean it, because Id have to buy 6 new tires and take a loss on 75% treaded 35's.... and the wife doesnt give me that much of an allowance and apparently my new job is out of the goodness of my heart...fuk you gov newsem
 

jeff

Moderator
We've got a ZR2 in the driveway and it's a fun little truck for what it is. But it's been kept 100% stock and it runs and drives exactly as designed. I would never run a 37" tire on the ZR2 unless we went full attack mode on it and at that point a lot of the electrics would get bypassed or eliminated. And the front end would get cut off. And probably back-halfed. The amount of money that it takes to exceed what the factory provides in terms of capability on a new truck is enough to make ya sick!

Are you driving your truck hard enough to break the rear differential or an axle shaft? If so... is it a weekend toy or a daily driver? Basically, if it does break on the weekend can you survive a work week without it?

Having looked over the Zr2 I would be far more worried about the front of the truck when running 37's. The rear axle would be toward the bottom of my list of worries. Things like the steering rack, ball-joints, tie rods / tie rod ends and hubs / bearings. If something up front on that short list fails you can't steer and you might just crash. If the rear driveline explodes you will most likely be able to maintain control of the truck. I don't know what all you have done to the truck to understand why the thought process involves replacing something that's relatively unlikely to break before all the other things that can go wrong are upgraded. Assuming you are driving hard enough to break the rear end have you considered how you are going to properly (and repeatedly) stop a 37" tire? Or installed a cage to prevent the roof from caving in if it goes belly up?

Aloha
 
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