junk yard 4.10s

[crazytb]

if i was to go to a junkyard or a place that is parting out a trailblazer how would i know if the axles i am getting are in fact the 4.10 or 3.73 vs my 3.42? are there differences outside teh box..numbers written or is it just hope for the best..i know these tbs have the 8in vs the other 8.6 so thats not a problem but whats about the internals.how do u know...then it would just be a staright sway right..it would probably be a pain for the front but easier then actually opening and messing with gear placement..am i wrong? if you do get a swap is a tune still good or do you need an upgrade? someone brought up a good poinit in another thread..the bigger gears do get less gas mileage but bringing the 3.42 up to speed kills it to..especially since i have the big tires..but engine burns gas up hills and getting started from a stop...the bigger gears should help..the 4.10s and a light foot should be fine with gas ...better then 3.42s and a lead foot no?

[AlekG]

if i was to go to a junkyard or a place that is parting out a trailblazer how would i know if the axles i am getting are in fact the 4.10 or 3.73 vs my 3.42? are there differences outside teh box..numbers written or is it just hope for the best..i know these tbs have the 8in vs the other 8.6 so thats not a problem but whats about the internals.how do u know...then it would just be a staright sway right..it would probably be a pain for the front but easier then actually opening and messing with gear placement..am i wrong? if you do get a swap is a tune still good or do you need an upgrade? someone brought up a good poinit in another thread..the bigger gears do get less gas mileage but bringing the 3.42 up to speed kills it to..especially since i have the big tires..but engine burns gas up hills and getting started from a stop...the bigger gears should help..the 4.10s and a light foot should be fine with gas ...better then 3.42s and a lead foot no?

There is a sticker somewhere that indicates both what gears are in the axles and if there is the locker. I think its in the glove box but you may need to do a search to confirm.

The only problem with swapping complete axles without opening them is you never know what the condition of the internals are. Are the locker gears chewed like mine were? Did someone abuse it and strip the axle or pinion splines? Etc.

For me its not an issue as I want to go up to 4.56 gears which means opening up both axles is a must.

Currently I have 33" tires which does throw the speedo off, but I have lived with it. Once I get the gears though, I will definitely need to recalibrate, either with an aftermarket device or by re-tuning. My tune is not locked so I will probably buy the software and change it myself.

AG

[crazytb]

which tune do you have..i haven't gotten mine calibrated either and your 4.56 gears seem to be a good choice.it seems inevitable that the box must be open just for piece of mind and as a better economic shoice but do the 4.56 gears from the h3 fit the 8in we have?

[AlekG]

I have the Wester's tune from Calgary.

I have been looking into 4.56 gears for a while now. Its not a straightforward thing for an I6 (with the 8" rear end).

For some background, read this (http://forums.trailvoy.com/showthread.php?t=22973).

Plus some more posts:
- specs (http://forums.trailvoy.com/showpost.php?p=314540&postcount=10)
- mutant (http://forums.trailvoy.com/showpost.php?p=319665&postcount=18)
- why? (http://forums.trailvoy.com/showpost.php?p=313548&postcount=6)

The quick story so far is that the H3 uses the 8.6" gears in the back and the 7.2" gears in the front.

I will go with Yukon gears which have 4.56 for the 7.2 and the 8.6. Nobody has anything above 4.10 for the 8" though. So thats where my talk of swapping the rear axle has come from.

However, there are developments all the time in regards to the rear axles so stay tuned ...

AG

[tylerfm]

Crazytb - You're looking for the RPO (glovebox) codes.

RPO codes:
GU6- 3.42
GT4- 3.73
GT5- 4.10
G80- locking rear diff

[crazytb]

no i kno my gears but thanks i have 3.42 GU6 i was just curious about Alekg and his quest for 4.56