Detroit Locker Slipping

[madcrzydrmr]

Did a search and couldn’t find any definitive Q/A about a Detroit Locker getting sloppy after proper use.

I put the thing in around 5 years ago (28 spline, still stock small bearing axles) and after a weekend on difficult, exercising trails, there is now an engaging type slop/slip feel when I hop into first and go forward. Lift clutch and you feel a quick engage of the rear diff in the butt of your seat. It feels and drives fine afterward. I lifted the rear end up and did a hand turn of the drivetrain and felt the slip/engage when I rocked the axles back and forth. Dana 20 in neutral. My first thought was maybe some of the splines on the stock axles stripped, but they are fine.

Is this normal behavior of a Detroit after its been womped on or is this the start of a failing locker? Again 28 spline, stock axles so I reckoned they would break way before the Detroit would.

 

[gr8scott]

Maybe perform the function check as described on page 8 of the manual.

https://static.summitracing.com/global/images/instructions/dtl-162c56a.pdf

 

[Rustytruck]

the old stand by function test was to put up one side just off the ground on a jack stand and try to carefully drive off with the wheel off the ground. if locked up it will drive off the stand. then check the other side. the Detroit gets clunky with different tire diameters on the same axle air one side down and not the other or a big difference in pressure sided to side. the Detroit has a big backlash in how far the driveshaft twists before getting tight in the pinion and ring gear. usually they either work or they don't. If you violently snap a axle shaft its pretty much 50/50 it takes out the Detroit too. My Detroit soft locker has been working flawlessly for over 30 years. My stock trac lock was wore out on 30,000 miles of street driving. My Trutrac up front been in there for 30 years to but it only works when in 4-wd.

 

[madcrzydrmr]

Thanks for the info. When it cools down outside, I’ll slap the 35’s back on and do more tests. It seems to lock and ran the rest of the trail just fine. Just now it has an inaudible pop feeling when taking off from a stop. It feels very similar to when I broke the original spider gears where it was missing some teeth and would slip a bit before it engaged.

 

[DirtDonk]

There are other things that can do that to a Bronco as well. So make sure you're feeling the locker rather than the driveshaft slip joint, or loose u-bolts.
You're probably on the right track with the Detroit, but it would not hurt to rule out all the other stuff too.

Paul

 

[broncogt]

Make sure your nut holding the pinion in is tight while your checking the driveshaft

 

[Rustytruck]

pull the drive shaft and check the splines, u-joints and the centering ball in the double cardigan joint when that ball and its roller bearings fail things get really weird down there as the joint tries to do its job.

 

[eb-nutt1]

Unfortunately, Detroit lockers are a lunchbox locker in a machined case...I exploded one in my 44 about 15 years ago when a axle joint exploded. Took the locker apart and all 4 locking rings had shattered, parts to repair were just about the cost of a new locker. Since I was rockcrawling at the time, just installed a full spool and never looked back...the looking rings inside are not very robust in size.

Brian

 

[sprdv1]

Did you ever sort it out..?

 

[madcrzydrmr]

Did you ever sort it out..?

I ran it through the locker paces per the manual and it locked/unlocked accordingly, although I could still feel a light/very brief slipping feeling once locked rotating the tires with my hands. This is what I think I might be feeling, but I haven’t had time yet to get back under and check the driveshaft splines, pinion nut, u-bolts, etc etc as mentioned above. I did however notice a minor rock mark on the driveshaft that looks like it got pinged from a large rock along with the muffler dented in... i rotated wheels watching the driveshaft I did see the pinion yoke wobble very slightly from side to side as it spun, so could be a loose nut, or something bent.