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Tarussell, or those with 5.86 gears....

SUBFAN

SUBFAN

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How do you really like those gears, and what do you use them for?

I am going to mostly run mud, but don't want to run out of RPM's putting the 241 in low range.

Will I have enough wheel speed keeping the motor under 5500 RPM's?

Can you just run through in 4 Hi?

I am looking into a D70 rear that needs regeared....I am thinking 4.56 is a little high, but they don't make 5.38's....
 
It messed me up seeing my name on a thread topic , Ha ,ha...

5.86's are great if that is what is needed/wanted .
What size tire are you going to run ?

Of all the trucks I have wheeled in with close to a 6 to 1 gear they have almost all had 44" tall tires and it has all been in the mud/swamp.
Each of these trucks have had really strong BBC's in them so wheel speed was never a problem and high range was always usable when fast tire speed was needed.

I choose 5.86's for my crawler Blazer because of the tooth contact vs. ratio for the D60/70 axles. It seemed to be the most gear with the most number of teeth in contact at any given moment and it was used in on the highway applications by several O.E.M.'s . My Blazer will not see too much road usage so highway RPM's are not a real concern and it is a good thing too - I am only running 36" tall SX's.

For wheeling off-road I have found it to usually be better to have more than enough gear and the option to up-shift when needed to gain wheel speed . I like to be able to have as slow of a tire speed as possible for control if needed.
If it is racing than I say go with as much tire speed as possible with just enough gear to keep the motor from working too hard.

I like the higher numerically gears not just for mechanical power ( lack of motor ) but for the slower wheel speed. If the motor is strong enough to hold the next gear up than wheel speed is still attainable.
Tom
 
like he said more teeth in contact with the ring gear is stronger. my friends have spun lots of tall gears in the mud and all were the vary small pinon count. puts more pressure on a smaller area.

so what will be the specs of the rig and its use ?
 
'90 Burb, 400 sbc - slightly built, D60/(70 P/L),700R4, 241, maybe a divorced 205 someday, 36" SX's for now....

Right now I plan on driving it to and from wheeling spots, which would consist of mostly mud....
 
If you're worried about 4.56s being too high for mud with a 2.73 low range, you need more motor. I use to play in the mud with a pretty stock 355/465/205 turning locked 4.10 axles and 44" TSLs and I usually used granny gear and 4HI in deep holes. I'm thinking if you already have 4.56s in both axles and you think you might need deeper gears, go with a doubler setup. It won't cost much more and it'll give you way more options.
 
I think in your case the additional gear will help out a lot - that Burb is a heavy b*stard. I would think you are not getting crazy wheel spin at high RPM's with a mild SBC 400 and all that traction due to weight in your Burb anyways.
You may find that it is easier on the motor to go to a higher gear in the tranny and let the motor work at a lower RPM and take advantage of the mechanical gear.
If you wheel in first gear than I would say that you are going to feel like the motor is always on valve float with every burp of the throttle but if you play around and find where the motor is happiest with the tranny gear selection than I think you will really like the strong gear feel.

As an example there are a few local truck's in my neck of the woods that amaze folks every time they go wheelin and both of them run relatively stock 454's but those that do not know think they have strong engines in them.
First truck is a mid eighty's K-10 with 44"s and 6.17 gears and the second truck is a late eighty's Burb with 5.13's and 44"s . Both trucks are able to get the tires spinning fairly well with the motor in a very usable RPM range because the motors feel no pain when they upshift.

A lot of folks get all weird about going with more gear than 4.56 but just think that a starting point for a basic truck with 31" tall tires should be around a 3.73 gear now add tire diameter - tire/wheel weight - weight of the vehicle - intended use - and amount of traction aggressive tires give you all in the equation and most trucks are way under geared . There is way more to it than just RPM at sixty miles per hour.

Tom
 
I usually WAY overthink a project....If I pick up the D70, it will need regeared to match the front, and I was thinking what might be the optimal gear....

I thought the 4.56's were a bit of a compromise with the 700R4, but that was to leave me the flexibility to switch to a T400 later on....

I would think by going with 5.86's it would kind of force me to stick with the 700R4....
 
Sounds like "MuddyBuddy" has a good thought with the 5.13's . Kind of a middle of the road gear choice for you ???
Try and drive someones truck that has a close gear/tire combo you are looking at and see how you like it and than make a decision.
Good luck !
Tom
 
i was originally gona run 5.13s wit 35's, but managed to find 42s before i got it running. havent tested it out yet, but it should be better than what i had before (3.73s and 35's)
 
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