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View Full Version : 4.88 Gear Manufacturers?


guruerror
11-24-2009, 11:25 PM
I recently performed the following mods:

K&N cold air intake
Gibson shorty headers
Flowmaster exhaust
Cognito upper control arm leveling kit
Cognito HD OEM-style tie rods
Cognito pitman/idler kit/support
Bilstein front shocks
37x12.50x17 BFG Mud Terrains

With the 37s the truck feels like it can't get out of it's own way. I've read through some posts regarding changing the gear ratio. I'm leaning toward 4.88s...most of my on-road driving is below 70 MPH and I rarely ever tow, so 4.88s seemed like a good choice. (feel free to chime in on this...as I do a fair amount of off-roading too)

My main question is; what is a solid brand to look for when shopping for gears?

twr
11-25-2009, 12:36 AM
Hi these are some of the best companys out there: RICHMOND, STRANGE, PRECISION GEAR i have used gears from all these companys and never had a problem. Their are some other good companys out their to. Just make sure the guy who installs them knows what he is doing and has all the correct tools to do the job correct. I would put new bearings and seals in at the same time. Hope this helps

OrangeCrush
11-26-2009, 09:42 PM
Go with precision. The other gear companies are good but for the price and quality, you can't beat precision.

The one company I wouldn't go with are ZOOM. I've used them in the past and went through several sets do to flaws in the castings.

Good choice on the 488's. My last H2 I installed 456's and wish I had gone up.

You'll see a post in a few minutes where I'm getting ready to discuss me installing a set of 488's next week. (and I've got a supercharger)


Mark

guruerror
11-28-2009, 01:48 AM
Thanks!

OrangeCrush
11-28-2009, 01:50 AM
I found precision's site but can't buy from them. I did a search and found a set of motive gears but only for the front.

I'm still looking, if I come up with a good price, I'll post it here.

Don't forget, you'll need an installation kit.


Mark

OrangeCrush
11-28-2009, 01:55 AM
I forgot about these....

http://www.trailduty.com/index.php?cPath=112_118_436&osCsid=fc8c18c4f6aee6020789b58be4130369

Probably one of the best prices and you know they'll be the right parts.


Mark

twr
11-28-2009, 02:22 AM
hi guruerror, Orange has got you the place to buy them, all you need now is someone to install them if you can't. If you have to get someone make sure he can you it correct. I have had to repair a few gear sets that were not installed correct, gear whine, wrong bearing perload, pinion leaks. I have been a mechanic for 26 years and have seen alot of very poor work done.

OrangeCrush
11-28-2009, 03:28 AM
Tracy hit it on the head.

You've got to have someone that knows what they are doing. GM gears are way harder than setting up Ford gears for instance.

I don't do trannys and gears.

Now I gotta find someone.


Mark

twr
11-28-2009, 04:00 AM
hi Mark, to bad your so far away or i would do them for you. Anyone doing gears has to have a pinion depth gauge, inch pound dial torque wrench, dial indicator, gear paint for checking the pattern and KNOW HOW TO READ THEM, spanner wrenchs in some cases and a few more tools but these are the main ones.

OrangeCrush
11-28-2009, 02:10 PM
hi Mark, to bad your so far away or i would do them for you. Anyone doing gears has to have a pinion depth gauge, inch pound dial torque wrench, dial indicator, gear paint for checking the pattern and KNOW HOW TO READ THEM, spanner wrenchs in some cases and a few more tools but these are the main ones.

Oh, I am well too aware of what is needed. The biggest tool needed is what you mentioned.... "KNOW HOW TO READ THEM"...lol.

My last H2 I had a friend (who is a GM tech) install gears. I went through 5, YES, 5 sets of ring and pinions)

The towing company that tows for my bodyshop couldn't believe how many times I would call stranded on the side of the road because the rearend would lock down.

That was the cheap part.... one of those times when the frt gears locked down, it shattered from front diff.

Hurts just to think about it.

Ended up taking my gears to another friend who is also a GM tech. Did it once and it was fixed.

MAKE SURE THE PERSON KNOWS WHAT HE IS DOING.... an incorrect installation of gears and you may have more than a whine (no pun intended)


Mark

twr
11-29-2009, 01:27 AM
hi Mark, my point exactly the the first GM tech shouldn't install gears and the second GM tech knows what he's doing. I have seen a few diff's locked up, some do to gears some carriers { pinion pin} bearing etc. This is also why you should only buy gears from a good company and make sure the guy know's what he's doing so you don't go throught it 2 times or in your case 5 times. THAT SUCKS

guruerror
11-30-2009, 03:31 PM
Thanks for the additional info...I'm on Trail Duty's site now.

As for installation...I've had my local dealer to all my work so far. They're kind of a niche dealer, they're all Corvettes, Hummers, and GMC trucks. They did the install for everything in my first post (minus the CIA, plus an oil change) for $1,600...and that included some custom work on the Flowmaster to keep it up under the truck like the stock pipes.

I hate to sidetrack my own post...BUT, after doing some more reading on the forum I find myself torn between 4.88s and 4.56s. I ordered the Superchips Cortex 2950 to reprogram the truck for the tire change and as a prep for the gear change, but I'm thinking that maybe the 4.56s would be a better pick for me.

I'll do some more research and perhaps open another thread once I can better articulate my questions/reasoning.

Thanks, Orange, for the Trail Duty link.

OrangeCrush
11-30-2009, 03:35 PM
I can only tell you my experience. I installed 4.56 gears the first time I installed 38's.

Now on this H2 with supercharger also installed, I'm going with 4.88's. I did the 56's last time and to be honest, even with a supercharger, I needed just a hair more. (thus why I'm going with 88's this time)

In either case, you'll see a big difference... I was just telling you from experience.


Mark

guruerror
12-01-2009, 11:36 PM
I went with the trailduty.com 4.56...

...more info regarding 'my gears' and my performance/mileage results can be found in my other post.

http://www.elcovaforums.com/forums/showthread.php?t=38624

Thanks for your feedback!

OrangeCrush
12-02-2009, 03:03 PM
I went with the trailduty.com 4.56...

...more info regarding 'my gears' and my performance/mileage results can be found in my other post.

http://www.elcovaforums.com/forums/showthread.php?t=38624

Thanks for your feedback!

Actually, I just did the same.

Yesterday I ordered a set of 4.88's from Summit. Even with the more expensive gear set (4.88's as opposed to 4.56's) it was cheaper to buy them from Summit plus I couldn't get trail duty to answer the phone.

Unfortunately the shipping date isn't for another almost 3 weeks so I too ordered from Trail Duty.

I did however buy the 4.56's because I'm 99% sure I'm doing the diesel conversion and the 4.56's will bring the truck right back to the stock gear ratio with my tires.


Mark

guruerror
12-02-2009, 03:21 PM
I'm saving my diesel conversion for 100,000 miles.

OrangeCrush
12-02-2009, 03:27 PM
Based on my current mileage, (50K) I'll put the other 50K mileage on in roughly 2-3 years.

Based on fuel savings of 4700 per year, I'll have saved well over 10-12K by doing the conversion now... almost enough to pay for the labor.

Mark