98fword,
Thanks for the help. Just out of curiousity, I ran the calculation for a 4.30 gear compared to a 3.55, and here's what I came up with: 4.30/3.55=1.21, 1.21x19=23-tooth speedo gear exactly. How much difference mileage/performance-wise would there be between a 4.10 and a 4.30? I really don't want it geared like a tractor, but if the difference is not that significant, that seems like a perfect match. Does somebody make 4.30's for a 8.8 rear end? And if so, how much should I expect to pay installed on a 4x2? I know that's a lot of questions, but you sound like you've had a lot of experience with this sort of thing. Thanks again.

 

ALLFORD,

You must have smaller tires than I do. Mine are the stock ORP tires, 265/70-17's. Before the gear change, at 2000 rpm I was running between 73 and 74 mph.

Way2,

The ring and pinions sets are seperate. A set for the front and one for the back. The pinion kit and/or mini kit are also seperate. I was able to get away with a mini kit for the front. It doesn't include pinion bearings like the full pinion kit does. The front pinion bearings were in good shape. Both include a measly assortment of pinion shims, but they are very thin. I guess they expect you to stack these thin shims to achieve the correct pinion depth. It is definately better to use one thick one if at all possible. Luckily the tech that did mine had a pretty good selection himself and was able to do just that. I think once you find someone you feel good about doing the job, ask him/her (lets not offend) what they want you to bring them. One mechanic may prefer a different brand of gear than another mechanic. Keep him happy by bringing him what he likes to work with. The only other thing I needed that wasn't included in my first posting was the speedo drive gear. I also bought an extra clip, just in case the original launched itself across the yard.

Fordman3,

4.30's with your setup is pretty low. The 4.10's with my setup feel really good. Not enough to kill you on milage, but still pulls nicely. If I were going to a tire 33" or larger I would probably have gone with lower gearing. That's only my opinion. Ask 10 people, get 10 different answers. According to my calculations, with the 4.30's in your truck, at 60 it'll be turning approx. 2050 rpm. At 70 it's almost 2400 rpm. I would think that would make the needle drop fairly quickly. And yes, several companies make 4.30's for the 8.8 rear. Parts and labor, you should expect to pay around the $500 to $600 range for quality gears, properly setup.

 

98wford,

If I were to have a 4-5" suspension lift on my 97 4x4 xlt sc (see sig), what would be the best tire size and gears? I would want to have good acceleration and decent highway,
more of the low end acceleration though, I don't mind running at higher rpms on the highway.

Any advice would be appreciated,
Thanks

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97F150 XLT SC 4x4 Flairside 4.6 V8 5sp Dk Toreador Red, 3.55LS
ARE tonneau cover, p255/70rx16 tires (came w/235), Superchip
Pioneer CD w/4 Polk Speakers, skid plates
bed liner, side window deflectors, reese hitch, K&N air filter
40s-2chamber Flowmaster, Bosch +4 spark plugs, rustproofing
Better Built Stainless nerf bars
heavy duty shocks

 

Spartan,

For advise on lift kits and larger tires there are guys on this board much more knowledgable than I. I haven't lifted my truck or put larger tires on.........yet. I'll take a shot though and invite additions and corrections. From what I gather, with a 4"-5" kit you can squeeze 35's in there. You'll get arguments for and against on that one. 33's will easily fit with no rubbing. I think if it were me, I would ask myself if I liked the way the gearing feels now. Lets say you do. Figure out what tires you want first, do the math and find out how much of a percentage change it's going to make. Choose a gear ratio with at least the same amount of change. I say at least because when you go to larger tires you lose some of your torque multiplication. Plus the tires are going to be a little heavier. Nothing robs power like adding rotational weight. So if you're going to err, do so on the low side. In other words, opt for a numerically higher ratio. Right now you should be turning about 1690 rpm at 60 mph with your current setup, 3.55's and 30.1" tires. Lets say you want a set of BFG 295/75R16's, which are about 33.4" diameter. To run that rpm at that mph with the new tires you would need a set of 3.94's. There's no such animal. The closest thing to that on the low side would be 4.10's. That would give you a little more grunt and a little higher rpm at highway speeds. If you're wanting a little more change the next step would be 4.30's. Go to www.4low.com. They have some neet little calculators. You can play with tire and gear changes to see what suites you best before you drop your hard earned dollars.

I'm sorry, I didn't see that you have a 5 speed tranny. I was figuring your mph/rpm based on an automatic. I'm not sure what the final drive ratio is for your tranny. It's all relative though. Just stick to percentage of change and you should be able to get a good idea of what to expect.------------------
98 F-150 XLT 4X4 ORP Super Cab Short Bed, 4.6, Auto, 4.10's, Magnacharger supercharger, Superchip, Gibson single cat-back, 80/100w German head lamps, Warn HS9500i winch with semi hidden mount, Wrangler dual battery kit with red & yellow top Optima batteries, Torsion bars cranked up 2.5 turns. Needs one more door.



[This message has been edited by 98fword (edited 09-04-2000).]

 

98fword,
Not to make this thread too long I know you are tired of all the repkying, Is your diff 9.75 and or limited slip, I have a 2000 F-150 auto 4x4 with the 9.75 diff 3.55LS but cant find gears (4.10) with LS, or probably not looking enough, I requested it through a distributor (Ford) and as per the dealer they only carry the 4.10's for the 8 diff. any advise??

------------------
2000 F-150, S/C F/S 5.4lt Auto, 3.55 LS, M4x4, Capt. Chairs 6 way elec.,DELETED 6 CD,Class III towing hitch and package, etc,etc,.
Med Toreador Red
Born 03-27-00
Mods,
Superchip UAT2,Borla Anniversary Edition Split rear catback,K&NGen II or FIPK, BBK Trottle Body,Granattely Mass Air Flow,SVT Lightning 18" wheels,285/60/18 Pirelli Scorpion Zero,HellwigSway bar,Dark Walnut dash kit,Muth signal mirrors,White face gauge,Bosch Plat. 4's,Retrax Rolltop,Outland sport bumper guard,Rancho rsx shocks,Ford OEM bug deflector,Underhood sound insulation panel,Piaa Plat. super white Bulbs,Catch All floor mats,Lund Back Draft tailgate spoiler,Pioneer DEH-920-R H/U, CDX-656 CD Changer, Polk DX 7 and Pioneer TSA-6895 Speakers, Steering Remote for H/U, Mute for cellular.

 

dragonboy,

I have 8.8's front and rear. Go to www.reiderracing.com. They show that they stock 4.10's for the 9.75 rear. Unless you were wanting a different type of limited slip, yours will work with the new gears.

------------------
98 F-150 XLT 4X4 ORP Super Cab Short Bed, 4.6, Auto, 4.10's, Magnacharger supercharger, Superchip, Gibson single cat-back, 80/100w German head lamps, Warn HS9500i winch with semi hidden mount, Wrangler dual battery kit with red & yellow top Optima batteries, Torsion bars cranked up 2.5 turns. Needs one more door.

 

98-

I was wondering what size rear end you have on your Expy? I called several places locally and they told me that they could not do it due to mine being 9.75".

Any replys would be appreciated! Thanks!

 

Way2,

Actually, I have 8.8's front and rear in my F-150. Reider Racing has 4.10's for 9.75 rears. I don't know why the shops you talked with can't do the install for you, other than their lack of qualifications! Search long and hard. You'll know you have the right shop when you get that warm and fuzzy feeling! I believe several others here with 9.75's have had 4.10's installed.

------------------
98 F-150 XLT 4X4 ORP Super Cab Short Bed, 4.6, Auto, 4.10's, Magnacharger supercharger, Superchip, Gibson single cat-back, 80/100w German head lamps, Warn HS9500i winch with semi hidden mount, Wrangler dual battery kit with red & yellow top Optima batteries, Torsion bars cranked up 2.5 turns. Needs one more door.

 

When did Ford go back to using a spedo gear? On my 96 the spedometer runs off of the exciter for the rear ring gear. When I put 4.56's in I just reprogrammed the spedometer.
Also, is the 8.8 in front a reverse rotation unit? I am asking because I may put 4.56's in my 99 Expy.

Mike

 

ksmike,

I'm not sure when Ford made any changes. I do know in a '98 with a 4R70W tranny there is a speedo drive gear that is changable.

The answer to your second question is yes. The 8.8 front differential in my truck is reverse rotation.

------------------
98 F-150 XLT 4X4 ORP Super Cab Short Bed, 4.6, Auto, 4.10's, Mag-Hytec diff. cover, Magnacharger supercharger, Superchip, Gibson single cat-back, 80/100w German head lamps, Warn HS9500i winch with semi hidden mount, Wrangler dual battery kit with red & yellow top Optima batteries, Torsion bars cranked up 2.5 turns. Needs one more door.

 

In the 98 4R70W with a 4:10 gear you can install either a 21 or 23 tooth gear for the speed correction from the 3:55 gear. There might be a speed limiter problem unless that is removed by a chip. I have been told to install the 23 tooth gear for what that is worth.

 

The number of teeth on your new speedo drive gear is going to be determined by the percentage of change in either gear ratio or tire size and how many teeth are on your existing speedo drive gear. Assuming your speedometer is correct to start with.

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98 F-150 XLT 4X4 ORP Super Cab Short Bed, 4.6, Auto, 4.10's, Mag-Hytec diff. cover, Magnacharger supercharger, Superchip, Gibson single cat-back, 80/100w German head lamps, Warn HS9500i winch with semi hidden mount, Wrangler dual battery kit with red & yellow top Optima batteries, Torsion bars cranked up 2.5 turns. Needs one more door.

 

Maybe the E4OD's and 4R100's are the ones that dont have a spedo gear. I dont see a spedo cable or gear on a 2000 Expy with a 5.4

Mike

[This message has been edited by ksmike (edited 09-19-2000).]

 

ksmike,

'98 was the last year that had a speedo drive gear that you could change to recalibrate the speedometer. '99 and up models have to be recalibrated using special equipment, Genstar tester or World Diagnostic. Just another effort by Ford to make you come to them for help.

------------------
98 F-150 XLT 4X4 ORP Super Cab Short Bed, 4.6, Auto, 4.10's, Mag-Hytec diff. cover, Magnacharger supercharger, Superchip, Gibson single cat-back, 80/100w German head lamps, Warn HS9500i winch with semi hidden mount, Wrangler dual battery kit with red & yellow top Optima batteries, Torsion bars cranked up 2.5 turns. Needs one more door.

 

Hey Dragon Boy!

Haven't heard from you in a long time, nice to "see" you back here again!

Hope everything is going well for you, drop us a line sometime!

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer