Another 10 Bolt G80 Locker Bites The Dust...

[df2x4]

I bet the owner's manual has instruction about lube change after ring 'n' pinion break-in.

My '97 owners manual does recommend a drain and fill of the rear axle at the first oil change (3000 miles) if equipped with a G80. If it's an open carrier they say just check the fluid level and go.

I've got about a thousand miles to go until my next oil change, I'll probably just do it then.

 

[Sean Buick 76]

When I bought a $3000 custom Mosier 12 bolt rear end his instructions were to drive it reasonably for 500-1000 miles, change the fluid and then give it the beans. 15 years later it’s still happy at 1000+ hp, in the car I sold.

 

[df2x4]

Digging this back up because I got curious about recommended break-in procedures this morning...

According to Eaton the TrueTrac carriers themselves require no break-in at all. Here's the direct quote from their "TrueTrac FAQ" page:

"While Truetrac units do not require a break-in for operation, the gears do “lap” together. While the time required to fully lap the gears will vary depending on driving style and loads, the units will operate smoother with age."

Source: https://www.eaton.com/us/en-us/prod...rket-differentials/detroit-truetrac-faqs.html

Richmond Gear's ring and pinion install manual calls for a few short heat cycles like @Supercharged111 mentioned. Here's what they say:

"A new ring and pinion installation, especially a high numeric ratio with new bearings, can cause an excessive heat buildup in the rear end and cause softening of the gear teeth and bearings if a break in is not performed.

Street vehicles should be driven at normal street driving speed for approximately 10 miles, then stop and let cool for 30 minutes. Do this 2 to 3 times. Towing vehicles need approximately 200 to 300 miles of normal street driving before being used for towing.

On circle track race cars make approximately 6 to 8 laps at slow speed, then let cool for 30 minutes. Make 6 to 8 more laps at slow speed, then 2 to 3 laps at full speed, then let cool again for 30 minutes.

Drag cars need only an initial run-in since they are driven short distances and heat is not normally a problem with proper lube and backlash allowance.
NOTE: If after the above break in is performed, overheating of the rear end is suspected, repeat the final portion of the break in procedures."

Here's a link to that manual, these instructions are on page 81: https://www.richmondgear.com/wp-content/uploads/pdfs/richmond/Richmond_Catalog_Section2.pdf

One interesting observation is that I see no mention of changing the oil after break-in in either document. I'll probably still do it just for the peace of mind, but now I'm curious if it's really necessary in my situation.

 

[scott2093]

Yukon Gear

The Ultimate Gear Break-In Guide: Ensuring Peak Performance and Longevity

Gear break-in is a crucial process that involves controlled heat cycling of the gear set to properly season and harden the contact surfaces as well as to polish and establish the final contact pattern on the gear face.

www.yukongear.com

 

[Scooterwrench]

Digging this back up because I got curious about recommended break-in procedures this morning...

According to Eaton the TrueTrac carriers themselves require no break-in at all. Here's the direct quote from their "TrueTrac FAQ" page:

"While Truetrac units do not require a break-in for operation, the gears do “lap” together. While the time required to fully lap the gears will vary depending on driving style and loads, the units will operate smoother with age."

Source: https://www.eaton.com/us/en-us/prod...rket-differentials/detroit-truetrac-faqs.html

Richmond Gear's ring and pinion install manual calls for a few short heat cycles like @Supercharged111 mentioned. Here's what they say:

"A new ring and pinion installation, especially a high numeric ratio with new bearings, can cause an excessive heat buildup in the rear end and cause softening of the gear teeth and bearings if a break in is not performed.

Street vehicles should be driven at normal street driving speed for approximately 10 miles, then stop and let cool for 30 minutes. Do this 2 to 3 times. Towing vehicles need approximately 200 to 300 miles of normal street driving before being used for towing.

On circle track race cars make approximately 6 to 8 laps at slow speed, then let cool for 30 minutes. Make 6 to 8 more laps at slow speed, then 2 to 3 laps at full speed, then let cool again for 30 minutes.

Drag cars need only an initial run-in since they are driven short distances and heat is not normally a problem with proper lube and backlash allowance.
NOTE: If after the above break in is performed, overheating of the rear end is suspected, repeat the final portion of the break in procedures."

Here's a link to that manual, these instructions are on page 81: https://www.richmondgear.com/wp-content/uploads/pdfs/richmond/Richmond_Catalog_Section2.pdf

One interesting observation is that I see no mention of changing the oil after break-in in either document. I'll probably still do it just for the peace of mind, but now I'm curious if it's really necessary in my situation.

They'll make a little metal during the first 1000 miles of use,make that your break in oil change interval.

 

[asjt3]

I put a trutrac in my 93 K1500 ten years ago after the G80 exploded while driving (center pin flew out because last owner/mechanic must not have tightened 8mm set-bolt properly). Pieces of the carrier were poking through the rear cover.

It has performed great, although sometimes because the rear of the pickup is light, I have to use the e-brakes to help it engage from a stop in snow/ice. I think the gear instructions were to change oil after 500-1000 miles, but I didn't for about 10,000 miles and it was fine, even then the oil looked brand new (although I did take a lot of time to ensure I got the gear tooth patterns perfect which probably minimized wear).

 

[df2x4]

I got impatient and tested the new setup a little bit yesterday evening. What a difference! Breaks both tires loose effortlessly and is so much more predictable than the G80 ever was.

Obviously time well tell the story of reliability, but so far I'd recommend these parts with no hesitation. I'm extremely happy with how the truck drives now.

 

[fancyTBI]

I tried breaking mine loose. With the sticky tires and hot weather it wouldn’t. The TBI was really showing its weaker side.

On another note, I’m changing the fluid Monday. Well, I’m not. The cover is leaking and ARS is going to replace it for me since they did the work last. I suspect that they didn’t take a ball-peen hammer to the back side of the bolt holes on the mating surface and flatten them out.

 

[df2x4]

I tried breaking mine loose. With the sticky tires and hot weather it wouldn’t. The TBI was really showing its weaker side.

Bummer. I really want to put a TrueTrac in my red truck now but I'm afraid the V6/4L80E combo would have similar troubles.

 

[Supercharged111]

Bummer. I really want to put a TrueTrac in my red truck now but I'm afraid the V6/4L80E combo would have similar troubles.

You can fix that problem ya know.