Changlng gears on tow vehicle

[gfarmcafe]

I've owned big blocks and a 40' diesel pusher, so fuel consumption isn't a huge concern as long as I don't have to give up the 42 gal. tank. Currently, I'm getting prices from our local speed shop to change gears, which they say will help without breaking the bank or leave us sitting beside the road. Thanks for everyone's comments and suggestions!

[A32Deuce]

Works for me. I understand wanting to keep what you have.

[WolfWhistle]

Let us know how it goes, G.
WW

[wuffwuff]

I might as well add my 2 cents. I have an 2002 RAM quad cab long bed 5.9l 2wd 3.55 ratio (w/trailer tow package) with 30,000 miles. When we retire and started Traveling 3 years ago it only had 9000 miles. Now why would I want to purchase a new tow vehicle. After a year of pulling a (with in towing specs) TT and getting frustrated with the high RPMs, I decided to try and fix the situation. After mulling it over during the winter months, I decided spending a couple of thousand buck on installing a Jasper axle assemble with 3.92 ratio was worth the upgrade. Now to the point, I do have better pulling power and the mileage stayed the same or better. I agree with gfarmcafe, why speed big bucks when all you need is 'just a little more' towing power.

PS ... with a complete housing change from Jasper you'll get new bearings, seals, etc and a three year warranty.

[Dodge Guy]

Originally Posted by grayfox

X-2

Non towing highway mileage will drop. Towing and around town mileage will go up. With lower gears (numerically higher) the engine has to work less to get and keep a load moving. However not towing on the hwy the engine will spin a bit faster which will use a bit more fuel. My empty hwy mileage dropped approx. .7mpg. However my towing and around town mileage went up by that same .7mpg. I don't drive my truck everyday so I have no issue losing that little bit of mileage for something that I will never see. For me towing is what my X does and I'm glad for the switch to 4.30's.

If you've done a gear ratio swap before then you'll know what I'm talking about!

[yetavon]

We are in the same boat as you, 97 Silverado with 206K miles, 2WD, 350 Auto with 3.42 gears, and live in the Smokies area, Loaded for camping we are around 5500 lbs, and have given serious thought and research to the same idea.
One thing I have not noticed mentioned is your tire size, 235/75/15 here, if you have a larger tire the will lower your overall ratio. One thing to also consider is most of the Mt roads you will be running lower speeds anyway so drop it a gear and enjoy the ride. As far as changing your gearing, Unless you tow several thousand miles a year, the cost to have it done wont be worth the return. The higher RPM means more fuel....period...overall gear change (axle) and ALL your driving is at a higher RPM, downshift and you have just temporarily changed your gearing. We hauled our 1600 lb sailboat 850 miles and averaged 17 MPG, 11-12 MPG with the camper, and believe it or not we have gotten 22mpg using non ethanol fuel and baby it running empty. With that said, I do have a plan on changing mine IF/WHEN I find the right parts, A 5 bolt rear axle with 3.73 gears and posi trac....It will then get a set of 3/4 ton springs and poly bushings. Unless I find a deal of another truck...;-)

[gfarmcafe]

Originally Posted by yetavon

We are in the same boat as you, 97 Silverado with 206K miles, 2WD, 350 Auto with 3.42 gears, and live in the Smokies area, Loaded for camping we are around 5500 lbs, and have given serious thought and research to the same idea.
One thing I have not noticed mentioned is your tire size, 235/75/15 here, if you have a larger tire the will lower your overall ratio. One thing to also consider is most of the Mt roads you will be running lower speeds anyway so drop it a gear and enjoy the ride. As far as changing your gearing, Unless you tow several thousand miles a year, the cost to have it done wont be worth the return. The higher RPM means more fuel....period...overall gear change (axle) and ALL your driving is at a higher RPM, downshift and you have just temporarily changed your gearing. We hauled our 1600 lb sailboat 850 miles and averaged 17 MPG, 11-12 MPG with the camper, and believe it or not we have gotten 22mpg using non ethanol fuel and baby it running empty. With that said, I do have a plan on changing mine IF/WHEN I find the right parts, A 5 bolt rear axle with 3.73 gears and posi trac....It will then get a set of 3/4 ton springs and poly bushings. Unless I find a deal of another truck...;-)

Thanks for your input. After talking to our local speed shop, they share most everyone's opinion. The initial cost will be around $1200. So, we'll just sit back and enjoy what we have now and decide what we'll do next Spring with both the trailer and Suburban. We too average 17mpg empty and love it.

Thanks for everyone's input on this. Despite our views of Forest River products, we love this forum and the people that contribute to help fellow owners. I might even decide to get another one!!

[Dodge Guy]

Originally Posted by yetavon

We are in the same boat as you, 97 Silverado with 206K miles, 2WD, 350 Auto with 3.42 gears, and live in the Smokies area, Loaded for camping we are around 5500 lbs, and have given serious thought and research to the same idea.
One thing I have not noticed mentioned is your tire size, 235/75/15 here, if you have a larger tire the will lower your overall ratio. One thing to also consider is most of the Mt roads you will be running lower speeds anyway so drop it a gear and enjoy the ride. As far as changing your gearing, Unless you tow several thousand miles a year, the cost to have it done wont be worth the return. The higher RPM means more fuel....period...overall gear change (axle) and ALL your driving is at a higher RPM, downshift and you have just temporarily changed your gearing. We hauled our 1600 lb sailboat 850 miles and averaged 17 MPG, 11-12 MPG with the camper, and believe it or not we have gotten 22mpg using non ethanol fuel and baby it running empty. With that said, I do have a plan on changing mine IF/WHEN I find the right parts, A 5 bolt rear axle with 3.73 gears and posi trac....It will then get a set of 3/4 ton springs and poly bushings. Unless I find a deal of another truck...;-)

As I have said it's not as simple as just dropping down a gear. If it was then the manuf. would not have different tow ratings with different gear ratios.

[WolfWhistle]

Originally Posted by Dodge Guy

As I have said it's not as simple as just dropping down a gear. If it was then the manuf. would not have different tow ratings with different gear ratios.

Lowering the gear ratio doesn't increase the factory ratings, as well.
WW

[Dodge Guy]

Originally Posted by WolfWhistle

Lowering the gear ratio doesn't increase the factory ratings, as well.
WW

Yes it does. with nothing more than a gear ratio difference, a tow rating can go up 4k lbs depending on the truck! even the GCWR will increase. obviously the GVWR will not change. however on some trucks the GVWR can go up.
it`s all dependent on the manuf., and how the truck is built.

[18CrewDually]

Originally Posted by Dodge Guy

Yes it does. with nothing more than a gear ratio difference, a tow rating can go up 4k lbs depending on the truck! even the GCWR will increase. obviously the GVWR will not change. however on some trucks the GVWR can go up.
it`s all dependent on the manuf., and how the truck is built.

I understand what you're saying and absolutely agree. Many owner's manuals will show this in a chart form. The only difference is the lower gear ratio in the rear and the GCWR can go up as seen in the chart attached.

But if your anal and concerned about weight police busting you for being over the advertised weight that is on the sticker in the door jam even though the truck now meets the higher weight spec, then it may raise concern.

None of this really has to do with the OP'S concerns so I apologize.

[WolfWhistle]

Originally Posted by Dodge Guy

Yes it does. with nothing more than a gear ratio difference, a tow rating can go up 4k lbs depending on the truck! even the GCWR will increase. obviously the GVWR will not change. however on some trucks the GVWR can go up.
it`s all dependent on the manuf., and how the truck is built.

You missed my point; I wasn't clear. My 2500 might have come with a couple different axles and the ratings will reflect that, depending on which truck I buy. But, what goes into the rating is what the factory does; it might not be only gears. Brakes, etc., factor in. The OPs Suburban came with those gears and changing gears to something not offered by the factory, or in fact offered by the factory, will not change what the factory rated the truck to tow. Granted, common sense says it should tow more weight, but when we were talking rating, and a shade tree mechanic doesn't get to rate anything. If it had stickers, we don't get to change the stickers
WW