Gears???

[92broncomann]

Ok so I have recently decided that I want to lower my gear ratio for my axles.

92 bronco

Dana 44 front IFS 3.55 stock

8.8 open 3.55 rear stock

33" BFG A/T's

My question to you good folks is what gears would you recommend?? 4.10's or 4.56's

I want to do 4.56's and a locker in the rear. However, I talked to my mechanic and he claims that if I do the 4.56's that I will absolutely hate my truck and want to take them back out.

With 4.56's the truck will shit and get off the line and do great off road, but is there really a difference between 3.55 and 4.10 or 4.10 and 4.56??

let me know this dilemma is quite irritating.

Thanks

 

[wileec]

Not sure with the Auto. I am thinking 456 for my m5od with 32s. Mine however is not a daily driver and I figure the OD will be enough to offset the high RPM on the highway.

In other words I would go 456.

 

[Yardape]

410 is a good ratio for 33's, its like stock with 355 gears and the stock 28 inch tall tires. 456's are perfect for 35's, I would go with the 456's for the extra giddy up and go. You have an overdrive tranny so that will more than make up for the lower gears on the highway. Plus its an added bonus if you decide to go with 35's down the road. Do it!!!!

 

[92broncomann]

alright im thinking ill for sure go with the 4.56's. i was looking up on Randy's Ring & Pinion calculator and with the E4OD trans going about 85 ill only be around 2900rpms if i remember right which isnt that bad. 4.56's it is /emoticons/[email protected] 2x" width="20" height="20" /> /emoticons/[email protected] 2x" width="20" height="20" />

 

[Miss Kitten]

i would have to put another vote in for 4:10's even though it sounds like you've already made your decision

 

[92broncomann]

My mind hasnt decided what to do. This is my daily driver and i dont want to cut the gas milage by any means she already gets around 11mpg 4.56 just sounds amazing for destroying anyhting off the line, but i dont want to lose my top end. so in reality 4.10's would be the better route to take.

someone tell me what to do LOL

 

[Miss Kitten]

ok the only comparisson i can give you is when i was looking into regearing my bronco. at the time i was daily driving the truck and using it off road.

it has 37" tires on it and we were having the debate of 4:10's and 4:56's. it was my brother that helped me see clearer on this decision when he told me how crappy my truck would drive on the street with the 4:56's. the deeper gears would have been great offroad, but i wouldn't have been able to hit very high speeds on the hiway.

it's still your decision to make broncomann, but with keeping 33" tires on your truck i believe that 4:10's will be plenty deep enough.

 

[Justshootme84]

If you're set on doing a gear change, i would also go with the 4.56's. You will haved much better pulling power than the 3.55's you have now. Changing gears in both axles will run you aboutg $1500 p&l, plus another $300 or so for the limited slip. There is a small bit of difference in power going from the 3.55's to 4.10's, but you'll prolly only notice that on the higway above 60 mph going up a hill with OD. If you get a chance, measure the actual height of your 33" tires as they're mounted on your rims. You may find that they're only 31.5" or 32" in actual height. Then use that new figure to calculate your cruising RPM's.

You say you already have a shift kit in the tranny, so that will give you some added umph with those 33's. Something else you could look into is swapping over to a used rear carrier with factory limited slip. You'll need to change the open carrier over anyway, as well as get a new one up front for gears over 3.92. JSM84

 

[92broncomann]

Wow, I never noticed that.... My 33"s are actually 31.5" tall LOL :lol:

I did some figureing at Randy's again and with 4.10's at "suggested" highway speed it is an optimum 2018rpm which is dead on for a SB. now at my usual speeds(about 10-20 over) 2329rpm and 2639........ not too bad LOL

4.10 RPMS:

65mph: 2018rpm

75mph: 2329rpm

85mph: 2639rpm

4.56 RPMS:

65mph: 2245rpm

75mph: 2590rpm

85mph: 2935rpm

A difference of about 2-300 rpm per cruising speed.

 

[Justshootme84]

92BM, what do you mostly use the bronco for? is it 90% daily driver, or 50/50 dd and offroad?

 

[vincendebbie]

92BM, what do you mostly use the bronco for? is it 90% daily driver, or 50/50 dd and offroad?

4:56's both front and rear. It will quicken your response off the line and still give you the chance to move up in tire size with no drag. A guy I know that lives across the street has 42's on his with 4:56's and with the NOS it pulls 14:20's off the line. --Vince

 

[92broncomann]

Shes a 90% daily driver, but i hit the trails as often as i can allow. I think im going to go with 4.10's