Gear Recommendations

[gtj]

Dear Group,

 

Have engine mods close to completion and checking the suspension parts. 6" lift kit going on with 14 bolt SF rear and 9.25" front diff, which will both be Eaton E-Locker equipped. They presently have 4.10 gearing.Will be running Toyo 315/75 X 16 tires, which measure out to 34.5" diameter.

 

Truck will see mainly highway 80%, bush roads 10%, and remaining 10% more off road stuff like sand/mud/snow.

 

In OD rpm for the 4.10 ratio shows 2090rpm @ 75mph/1672rpm @ 60mph and the 4.56 ratio shows 2325rpm @ 75mph/1860rpm @ 60mph.

 

I see most folks recommend 4.56 ratio here through the search, but was wondering if that's for a high true off-road percentage use. Any opinions welcomed.

 

Thanking You Advance,

Glenn

[srlbotanical]

What year is the burb? does it have a solid front axle? (pre 91' if I remember right)

 

If you have IFS I would not put a locker up front. I would go with a limited slip like the detroit truetrac.

 

If you have the money to re-gear, I'd go with the 4.56 gears. It's not like your driving it for the gas mileage anyway!

 

Also, I like the idea of a limited slip front and rear as apposed to lockers. It sounds to me like lockers would be over-kill in your situation. Its amazing what a good LS can do with throttle and some left foot brake control.

 

Steve

[grayghst]

I am running 4:10's with 35's. It runs good, decent mileage 16-18 mpg, but if you are doing a swap from say 3:73's I would go to 4:56's.

[gtj]

What year is the burb? does it have a solid front axle? (pre 91' if I remember right)

 

If you have IFS I would not put a locker up front. I would go with a limited slip like the detroit truetrac.

 

If you have the money to re-gear, I'd go with the 4.56 gears. It's not like your driving it for the gas mileage anyway!

 

Also, I like the idea of a limited slip front and rear as apposed to lockers. It sounds to me like lockers would be over-kill in your situation. Its amazing what a good LS can do with throttle and some left foot brake control. 

 

Steve

 

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Hi Steve,

The Burb is a 1995 model, yes, IFS.

I was wanting the locker in front so I could pull up on to logs, rocks and jut-outs rather than do the slam and bump technique which I would think increases the breakage risks.

Thanks for the opinion on the gear ratio.

 

Cheers,

Glenn

[gtj]

I am running 4:10's with 35's. It runs good, decent mileage 16-18 mpg, but if you are doing a swap from say 3:73's I would go to 4:56's.

 

<{POST_SNAPBACK}>

 

 

 

Hi grayghst,

 

If you had the 4.10 ratio in before the 35's" went on, what difference did you notice in power/acceleration between the stock tires and the 35's?

 

Thanks,

Glenn

[03HD]

I had the 4.10's prior to and after my 35's. the power difference was drastic, IMO. The truck would downshift all the time on even small inclines, it had way less get-up-and-go.

for your use I would recommend the 4.56's if you run alot on the highway, I went with 4.88's and love them. The mpg is still better than the corrected 4.10's because the engine is not working as hard to be in it's optimum zone, and all the low end grunt is back!

 

There is a chance when these tires are dead I will go with 36's or 37's, so that is another reason I went ahead and got the 4.88's.

[grayghst]

Hi grayghst,

 

If you had the 4.10 ratio in before the 35's" went on, what difference did you notice in power/acceleration between the stock tires and the 35's?

 

Thanks,

Glenn

 

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It's hard to say. I installed a westers tune the same day I lifted it. I really didn't notice a big difference in anything. The excelleration is a little slower, you can't really notice it though. Hope this helps.

[gtj]

I had the 4.10's prior to and after my 35's.  the power difference was drastic, IMO.  The truck would downshift all the time on even small inclines, it had way less get-up-and-go.

for your use I would recommend the 4.56's if you run alot on the highway, I went with 4.88's and love them.  The mpg is still better than the corrected 4.10's because the engine is not working as hard to be in it's optimum zone, and all the low end grunt is back!

 

There is a chance when these tires are dead I will go with 36's or 37's, so that is another reason I went ahead and got the 4.88's.

 

<{POST_SNAPBACK}>

 

 

 

Thanks for the informative response. As I have 3.42's presently, I have to drive friend's trucks in order to get a feel for what to expect. I can understand your choice of the 4.88's if you're going with 37" tires soon.

 

I have decided to go with the 4.56 ratio.

 

Did you research the gear manufacturers much before deciding on Precision? Have you been happy with the Precision product?

 

Thanks Again,

Glenn

[r8rs4lf]

I used to have an '88 K-5 that had 33" Thornbirds with 4:56 gears and an eaton posi. I loved that set up. It didn't rev too high on the highway because I had the 700R-4 tranny.

[03HD]

 

 

Did you research the gear manufacturers much before deciding on Precision? Have you been happy with the Precision product?

 

Thanks Again,

Glenn

 

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Yes, I did a lot of research. At least a week or more just reading forums everywhere getting opinions. I originally ordered a set of Yukon's but the front were on back order and I couln't find them anywhere online or otherwise. So I went with the Precision and have had no problem at all...no noise, no whine, no grinding, etc. I did hoever hear alot of bad about the Genuine Gears from 4Wheel Parts being nothing but Genuine Crap. I have no personal use of them, but it seemed like 9 of 10 people had bad experiences. They are cheaper and have a Lifetime warranty, but the warranty doesn't cover labor and that is almost as much as the gears. I didn't want to take the chance and wind up doing it twice, so I went with the Precision.

[gtj]

Yes, I did a lot of research. At least a week or more just reading forums everywhere getting opinions. I originally ordered a set of Yukon's but the front were on back order and I couln't find them anywhere online or otherwise. So I went with the Precision and have had no problem at all...no noise, no whine, no grinding, etc. I did hoever hear alot of bad about the Genuine Gears from 4Wheel Parts being nothing but Genuine Crap. I have no personal use of them, but it seemed like 9 of 10 people had bad experiences. They are cheaper and have a Lifetime warranty, but the warranty doesn't cover labor and that is almost as much as the gears. I didn't want to take the chance and wind up doing it twice, so I went with the Precision.

 

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Thanks 03HD,

 

Going with the Precision 4.56.