Changing the gears in my suburban

[LanceRKeys]

I have decided to change the gears in my suburban (2008 5.3L 4sp auto), but not sure how much of a change to make. I currently have 3.73 gears, and was thinking 4.30 because 4.10 doesn't change much, and 4.56 may be a little too much. I have read many accounts where people thought it was great, some where people wish they had gone more, but never of someone wishing they had not changed anything. Has anyone here changed their gears and regretted the decision? If so why? Anyone think 4.30 is the wrong choice?

Last but not least, just to be clear, I am NOT trying to save on gas by changing gears. I do not plan on ever getting my money back, just trying to give my suburban a little boost in towing power.

[Huntindog]

jerem0621 wrote:
I think this is a good idea OP. Seems every answer on this forum ends with get a 3/4 Ton. Gets really really old.



Jeremiah

Well some people are slow learners and need to be told more than once.

Others never learn.

Just about everyone here started out with less TV than ideal.

Most of us learned along the way, and no longer do that.

I still have serious doubts about the OPs ability to successfully change his own gears. His knowledge base doesn't seem to be that of someone that has done it, or anything approaching it before.

[blt2ski]

intheburbs,

Are you saying the SF 9.5" RA in my 8 lug GM C2500 is not worth having? or its going to blow up on me? I've had more issues with GM's POS auto transmissions than I have the SF9.5 RA's I've had. 30K blowup and get a rebuild auto trans like clockwork.......The one in my C2500 is the first TH400/4l80E derivative I've had with more than 40K miles. Actually has over 100K which is unbelievable in my book!
With this said, the GM RA's in the 15 series rigs with 5 or 6 lugs, do not do well when subjected to heat via towing or equal, generally speaking. So upgrading trucks, getting an aftermarket cover that hold more oil, has fins for better cooling as mentioned is probably a good idea!

marty

[intheburbs]

jerem0621 wrote:
I think this is a good idea OP. Seems every answer on this forum ends with get a 3/4 Ton. Gets really really old.

You know what got really old for me? Having breakdowns while on vacation because my half-ton Suburban's rear axle failed. I maintained it religiously, checked my weights on every trip, never was over, yet I had two catastrophic failures of the rear axle. It was a lot of fun explaining to my kids why we were spending four days in Youngstown, OH and Mitchell SD, instead of places like Colonial Williamsburg, Rushmore or Yellowstone.

When I sold that truck, it was on rear axle number four. Half-ton trucks just can't cut it with their semifloater rear ends. They're not meant for heavy/long-distance towing. I have a 10.5" full floater in my 3/4 ton Burb that AA rates to 10,000 lbs.

My current trailer is the heaviest I've ever pulled, yet it's also the least stressful to tow. No sway, no push-pull from semis, just a pleasant, stable ride. Eagle-eyed readers will grasp the enormity of that statement.

I'm just trying to share my experiences, hoping others might be able to avoid the problems I had, trying to do too much with a half-ton.

[jerem0621]

I think this is a good idea OP. Seems every answer on this forum ends with get a 3/4 Ton. Gets really really old.

I walked that road and I am very glad to be back in my Half Ton coming from a one ton LB CC Dually.

I have a F150 with the 8.8 rear axle. I’ve about got it set up for towing a smaller TT the way I like it.

Have you thought about getting a finned differential Cover? I’ve thought about it but I am not sure if it actually helps that much. They are cheap enough for sure. One big thing I like is the fact that you can buy the diff covers with a tap that you can install a temp sending unit. Something I would very much like to have.

I do think investing in a good OBD2 monitoring system such as the Edge System is prudent.

Thanks!

Jeremiah

[spud1957]

bucky wrote:
Make sure that V10 is the 3 valve version if you can find one.

Never available in the Excursion.

[mkirsch]

If your 2008 Burb still has the 4L60E in it, you probably don't want to re-gear it so it can tow in OD, because the OD gears in those transmissions are reportedly weak, or so I've been told, and read in multiple places such as this site.

Another thing you do NOT want to do is regear and end up turning the same RPMs in OD as you were in direct before the gear change. You've gained nothing from a bunch of work and expense.

[BurbMan]

Since only 2WD and you can DIY it, then it's certainly worth a try, if you don't like it you can change it back. Probably ought to add a trans cooler if you haven't already.

My only caution is that doing mods to make a 1500 tow better is a slippery slope. I went down this path with a 2000 Expedition until I came to the conclusion that I could spend as much money as I wanted but the truck would never tow like a 2500. Every mod helps a little, but you never seem to be quite able to get there. Lots of others here on the forum have reported similar experiences.

Not saying don't do it, just sharing some experience. To your question, I would go with the 4.30's, you should see a nice improvement. 4.56 is pretty deep and the truck will be screaming at highway speeds when not towing.

V-10 Excursion owners have reported that re-gearing from 3.73 to 4.30 really makes the truck a lot more driveable when towing heavy.

[pcaffrey]

Having worked in the auto service field for many years changing ring and pinion assy. and setting up properly is a pain in the. Look thru the salvage yards and get a good complete used rear end assy. in the ratio you want. Probably be cheaper and easier.

[LanceRKeys]

Yes I know how to set the gears up correctly, I looked it up on YouTube while staying at a holiday inn express last night (sarcasm). Actually I can set up the gears and have the tools, but being able to do so, understanding the math behind the gear changes and how it actually changes the characteristics of the towing experience are two different things. Sometimes you just have to talk to someone who has been there and done that. If nothing else, it made for some good conversation and cheap entertainment.

[K3WE]

Owned three Suburbans now...3.42 4-speed half ton, 4.10 4-speed half ton. 3.74 6-speed 3/4 ton.

I continue to be amazed at how much time the 6-speed truck spends in 4th gear and 3000+ RPM.

The more I drive, the more I wish I had a higher-geared rear end, so that the RPM's in 4th gear would be a little lower...

NONE of the vehicles want to do much of anything in "high gear"...and ALL THREE are very quick to drop all the way down to 4000 RPM gear ranges- I understand that there is a time and place for that, but it seems to come too often and too quickly.

Camper: 27 ft, 7000 lb gross weight, speed 65 to 75 MPH.

Comment to the weight police...While the 1/2 ton vehicles towed ok, there is a lot to be said for the heavier springs...and more about HANDLING than PULLING...and it's sort of a maxed out/marginal performance feeling on the half tons versus a 'competent' feeling with the 3/4 ton.

[LVJJJ]

Gearsplitter

[bucky]

Make sure that V10 is the 3 valve version if you can find one.

[Ralph_Cramden]

Turtle n Peeps wrote:

Huntindog wrote:
I don't mean to come across the wrong way..
Have you ever changed gears before?

It is pretty far above the skill level of the average wrench. Getting it wrong will mean a short life for the gears.

What special tools do you have to do the job?

Usually someone that has the ability to do this job, would also have enough knowledge to not need to ask a question about it online.

And yes, I have done it, but first I did many other things that were easier like motor/tranny builds etc.

LOL, I was going to ask the EXACT same questions!

Yep, I was thinking that also. Not exactly plug and play.

[Turtle_n_Peeps]

Huntindog wrote:
I don't mean to come across the wrong way..
Have you ever changed gears before?

It is pretty far above the skill level of the average wrench. Getting it wrong will mean a short life for the gears.

What special tools do you have to do the job?

Usually someone that has the ability to do this job, would also have enough knowledge to not need to ask a question about it online.

And yes, I have done it, but first I did many other things that were easier like motor/tranny builds etc.

LOL, I was going to ask the EXACT same questions!

[Huntindog]

I don't mean to come across the wrong way..
Have you ever changed gears before?

It is pretty far above the skill level of the average wrench. Getting it wrong will mean a short life for the gears.

What special tools do you have to do the job?

Usually someone that has the ability to do this job, would also have enough knowledge to not need to ask a question about it online.

And yes, I have done it, but first I did many other things that were easier like motor/tranny builds etc.