I wanna swap guts on my 14 bolts. Advice needed

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SquareRoot

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So I want to verify that the annoying harshness in my drivetrain is due to the Detroit Locker in my 14FF. I never noticed this before I swapped the th400 for the nv4500. If its indeed the locker, its getting replaced with an ARB, but at $1ooo bucks I want to be sure before I go down this path.

So, I'm thinking that I have 2 options. One is to pull to rear-end and swap back in the original 14 SF with the OE open rear-end and drive it for awhile. Although inexpensive, its a lot of work.

Or, maybe just pull the locker out and see if I can stick some OE parts in it for awhile. I have never been inside a 14bolt. I "think" I can just remove the locker and install some spider gears and have an open diff? I don't know, that's why I'm asking. If I'm not removing the carrier, there's no setup involved. I know it will be different if I put in the ARB, that's no big deal when the time comes.

The process should be just the opposite of installing a locker.....right?
 

Curt

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Yes,you are correct.The process is just the opposite.Assuming you have the spider gears,thrust washers.Just mark the spanner nuts with how many turns to take carrier out,put back the same.I’d personally check backlash anyway before putting cover on.

How long has this 14 bolt with the locker been under the truck?I ask only to know if this is a recent development or a new issue?I also have have a no spin in the FF14 bolt and every great once in awhile it will unlock when on gravel,throttle let off of.

Other than that,it’s been a trouble free unit.I also noticed we both have manual trans,or did.Obviously if the issue is new,I’d say the automatic is the issue.I’ve never drove a auto with a Detroit,but many was made in the factory CUCV.

I wouldn’t go back to the SF 14 Bolt.
 

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It's only been noticeable since I put in the 4500. I expected it to feel like a manual trans but this is excessive.

I had an idea this morning. I'm gonna pull the rear driveshaft and stick a yoke or a plastic plug in the tail housing to keep the fluid in the t-case. Then I can drive it around the driveway and see what happens. If it stops, I know it's the rear end. The axle/locker are in great shape, well maintained, low milage cucv unit. If it's the nature of the locker, it's getting replaced with an ARB.
 

dvdswan

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So I want to verify that the annoying harshness in my drivetrain is due to the Detroit Locker in my 14FF. I never noticed this before I swapped the th400 for the nv4500.

So describe the harshness...

You didn't notice with the automatic but you do with the manual. I would verify all the items swapped when you did the NV4500 before blaming something that was there with both transmissions.
 

SquareRoot

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So describe the harshness...

You didn't notice with the automatic but you do with the manual. I would verify all the items swapped when you did the NV4500 before blaming something that was there with both transmissions.
I think it was there before the swap. The nature of an automatic aka, "slushbox" masked the locking/unlocking of the locker that's being transferred thru the direct drive of a manual trans.
 

Curt

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Oh hell,you swapped in a 4500.For some reason I was a bit dyslexic yesterday morning.

Obviously the no spin is not gonna match the street manners like a open differential.I’ve heard that older Detroit lockers was pretty rough,not sure.The one I have now seems a bit harsher than the last unit,but the last 14 bolt had quite a bit of slop in the ring and pinion.This one here is a newer gearset.

I’d take the cover off and look for anything abnormal.There’s directions for how to test the locker for proper operation,probably videos…. https://www.eaton.com/ecm/groups/public/@pub/@eaton/@vehicle/documents/content/pct_1087652.pdf

What is it exactly doing?

I also adapted my driving to the truck and just learned how to drive it with an automatic locking differential.My sound dumb,but my new Toyota with a standard drives completely different.
 

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