My 4.56's ruined after only 9 passes and zero street miles???
Jan 31, 2010 | 08:47 AM
#13
I agree. Gears that are installed perfect do not require breakin. I drove 80mph on a brand new silverado from Oklahoma to Minneapolis non-stop and never had any rear end problems. This "break-in" talk that people always give you is for installers who can't quite get it right when installing the gears so they leave it at "good enough" and tell you to break it in.
Jan 31, 2010 | 08:55 AM
#14
I just had my 4.56's replaced with 4.10's and my rearend builder called me and was like "these gears (the 4.56's) are already trashed man". He showed them to me when I picked up the rearend and I asked him what caused it and all he could figure from looking at them was too much power. I thought this was kindof strange given what I run but who knows. The best way to describe what the gear looked like is this. On the teeth of both the ring gear and the pinion you can always see the normal wear pattern as it is shiny. The gears had this shiny wear pattern, but in the middle of this shiny pattern on all the teeth (both ring and pinion) there was a black (looks burnt) patch running long ways with the teeth. I hope I'm explaining this right??? Does this sound right to yall? I don't know much about setting up gears, so I don't know. I literally had only 9 passes on these gears and thats it. They were GM gears, not that cheap **** either.
My next concern is that this guy maybe wanted my good used 4.56's for his own benefit and showed me another set that had been torn up. I don't know. Doesn't seem to me that I'm at that power level yet that I have to worry about this. Or am I?
My next concern is that this guy maybe wanted my good used 4.56's for his own benefit and showed me another set that had been torn up. I don't know. Doesn't seem to me that I'm at that power level yet that I have to worry about this. Or am I?
Jan 31, 2010 | 09:17 AM
#16
Ben, so are u sayin u setup your rearend, & add new fluid. Break them in, then change out fluid that may've only been there for a bit, say 500 miles (whatever, pick a #) before beatin on it & then swap that for brand new fluid?
Or did u just mean add fresh fluid when doin rear, take it easy, then thrash on it? Cause this is what I'm thinkin. I prolly just read into it too much.
Or did u just mean add fresh fluid when doin rear, take it easy, then thrash on it? Cause this is what I'm thinkin. I prolly just read into it too much.
yeah, I normally set them up, do a little break-in and pull the cover again. I'm a little meticulous like that though LOL. I really dont do it for the sole purpose of changing fluid, its more to inspect whats going on in there, add fresh gear oil, put the cover back on and forget about it
Jan 31, 2010 | 09:50 AM
#17
I agree. Gears that are installed perfect do not require breakin. I drove 80mph on a brand new silverado from Oklahoma to Minneapolis non-stop and never had any rear end problems. This "break-in" talk that people always give you is for installers who can't quite get it right when installing the gears so they leave it at "good enough" and tell you to break it in.
Jan 31, 2010 | 10:12 AM
#18
yeah, I normally set them up, do a little break-in and pull the cover again. I'm a little meticulous like that though LOL. I really dont do it for the sole purpose of changing fluid, its more to inspect whats going on in there, add fresh gear oil, put the cover back on and forget about it
I've never heard a bad thing bout OEM (unless a person didn't like their ratio). After that my list would be short, but I hear good thing bout Yukon. I'd consider Richmond. Any others, I'd have to do my homework, but I may've forgot someone. I want a quiet gear myself; so if I ever go 3.73, it'll prolly be OEM or Yukon.
Ben, I can appreciate being particular.
I knew u did it for the inspection side of things, not just fluid change. I just wanted to know if u did fluid change @ time of swap, then after break-in too? Even tho I've never done any rears, other than R&R axle assy. & pullin rear cover to inspect/ see what I blew, I know lash/ seup is key. I believe in breakin even if someone said it was setup up proper. I mean really, how hard is it to pamper for a bit before cuttin loose?It'll save a person possible $, another visit & more of my time to a shop. It's a easy solution.
Now if I swapped 2 gearsets, I could verify by doin no breakin on 1 vs breakin on another, that would answer it for me.
I know what I want in a rear: No noise, durabilty, longevity. That's it!
I might not know how to setup a rear, or tear apart a 60e (can't be much more than a 350THM w/. OD, which I've done once), & rebuilt 1 engine. It's knowledge, goods parts to me. If I'm doin myself, it's different systems on a vehicle, knowin how to setup which ever you're workin on. If I lack the skills, time or knowhow, I still know what I'm lookin for in end product. I have most tools except some specialty stuff that could come up.
Jan 31, 2010 | 01:46 PM
#19
On a street vehicle, it would be silly not to break em in just to be safe, but a car/truck that gets trailer-ed to the track doesn't have the luxury of 500 street miles, so you have to hope that the set up is spot on and start making your passes, changing the fluid after about 2000 passes (500 miles 
). BTW, AAM are OEM gears IIRC.
). BTW, AAM are OEM gears IIRC.
