Bolt on Additional Gear on 4L60-E?

[Karnifax]

I have a 2000 GMC Yukon 5.3L with the 4L60-E Automatic transmission. I drive at highway speeds often and would really get a lot of use out of a "6th speed" I know the 4L60s-E is a 4speed with an electronic overdrive...but I wanted to know if there is a bolt-on additional gear etc. If not, what 6 speed transmission would swap in, and what dollars ($) value am I looking at? Thanks.

[HaulnA$$]

I have a 2000 GMC Yukon 5.3L with the 4L60-E Automatic transmission. I drive at highway speeds often and would really get a lot of use out of a "6th speed" I know the 4L60s-E is a 4speed with an electronic overdrive...but I wanted to know if there is a bolt-on additional gear etc. If not, what 6 speed transmission would swap in, and what dollars ($) value am I looking at? Thanks.You could install a Gear Vendors overdrive unit. Check them out here http://www.gearvendors.com/cg2wd4s.html . I have a friend with an '89 C2500HD 4WD with a 700R4, tall gears, and a Gear Vendors unit. It works well. HTH

[cancritter]

gear vendors..pricey ...am looking at getting one myself

[Karnifax]

Those prices- are they for a full GV 4L60-E Made transmission, or just for the additional unit that gives it a double OD? It looks like this unit adds an OD in every gear, am I reading this correctly? Thanks for the help!

[Koots]

kinda like in between gears. like 2,2.5,3,3.5,etc.

[Karnifax]

Is there a cheaper option, I don't have that kind of money.

[Koots]

If your sticking with auto transmissions you are out of luck. the 4L60E and the 4L80E are the newest autos you can get for the FS trucks. the new 6 speed transmissions might be perfect but they probably cost an arm and a leg right now. i would suggest getting a 5 speed NV4500 manual transmission from an early 90 3/4,1 ton trucks. it offers an excellent gear spread and is strong as well.

[96ImpSS]

Karnifax, Are you considering this from a gas mileage or engine longevity standpoint? With the mild 3.73 gears that you already have in your truck, believe it or not, you are very near optimum rpms in 4th gear for both of those considerations.
The only mod that would be cost-efficient from a fuel mileage standpoint, and would make the truck more enjoyable to drive, would be a mail order tune from pcmforless.com. He's really good on the late model trucks and usually squeezes an extra 1 mpg out of them.

[Karnifax]

Well I had read about a double-OD bolt on that allowed you to lower your RPMs. I restored a 1970 Corvette with my dad and I know they make a bolt on 5th-Speed for it, and just wanted to know if there was a similar option for my 4L60-E tranny, but I am not looking at spending thousands of Dollars to get there. I was just curious, and if it was cost effective enough, possibly get it. I can ask my local shop, I bet they will know, or can find out.

[Koots]

Who makes it? and do you have a link? i have never heard about that before, but there might be a reason.

[BLOWN91350SS]

We are working on the 6L80E at work so it's coming.....

6 speed auto for GM FS trucks.

[Koots]

I can't wait until they are cheap enough to start retro fitting without taking out a second mortgage or getting a loan. Wait til some dummies start boy racing their new trucks and crash em. than I will benefit from their unfortunate mistakes.