By Grady on Thursday, July 05, 2001 - 07:34 pm: Edit

After installing bumpers, lift, sliders, HD driveshaft, and 245/75's with steel rims on my '95 automatic, the gas milage and power is really driving me nuts. I have to cummute over a 2000' mountain everyday. I'd like to switch gearing so that I get a little better power than when the truck was bone stock with 235's. But would also like to be able to cruise down the freeway at 80 still. Which gears would work better for me the 3.80's or 4.10's?

By Ho Chung (Ho) on Thursday, July 05, 2001 - 07:51 pm: Edit

with 235/85 and 4.10 gears, i felt that it was the perfect gearing. hwy performance was real good.
not only because the gearing was lower, but because the rpm range that the 4.10 gears give you is the "happy range" of the disco v8. i was real happy with it.
in low range, i got that engine compression braking back and more.

i know one person that had 4.10 and 245/75...
seemed to be happy, but said rpm was a bit too high during hwy cruising. he was considering going to 265/75-16.

haven't done the math, but 3.80 sounds like would work well with 245/75.

would you consider going to taller tires later?
if thast' the case, 4.10 would be the ticket.

good luck.

By RVR OVR (Tom) on Thursday, July 05, 2001 - 07:55 pm: Edit

I agree with Ho. 32" or a little taller seems to be the sweet combo for the 4.10's to me (265/75's, 32.3" swampers both work well). The 245's would seem a little too small for 80mph cruising. As one four wheel mag put it "Upgrade your gears to a ratio a bit more than you think. Try it out, if it doesn't work, you'll have a great excuse for taller tires!"

Tom

By Mike J. (Mudd) on Friday, July 06, 2001 - 03:51 am: Edit

I hope you guys can handle my newness but what is the stock ratio?

By Kyle Van Tassel (Kyle) on Friday, July 06, 2001 - 04:01 am: Edit

3.54

By nadim on Friday, July 06, 2001 - 08:31 am: Edit

I got 4.7s with my 32.2....but that is only coz there are no 4.1s in Lebanon...I would have prefered the 4.1s coz they are supposedly stronger...but then again, i am planning on going with bigger tires...so the 4.7s are great...plus now it really C R A W L S!

By MA on Monday, July 09, 2001 - 05:29 pm: Edit

Where can you buy 3.80 gearing? How much do they cost? Is that what they use on Defenders?

By Neil Flanagan (Electriceel) on Monday, July 09, 2001 - 06:46 pm: Edit

3.54 is also stock for the Defender. I've switched to Ashcroft 4.11's to handle the 265/85 (33.7") Buckshots. I also have hardened halfshafts and have'n broken anything yet(knock knock knock)

You can get the Ashcroft stuff (located in the UK) at:
www.autoconv.com
If I have to do it again, I'll go with GBR:
www.greatbasinrovers.com
Not that I'm displeased pleased with Ashcroft, I'd just prefer to buy American...
<guilt-ridden, British and German car buying grin...>

Neil
94 D90 #1092
97 Disco
97 Triumph T509
01 BMW 330xi

By MTB on Monday, July 09, 2001 - 09:00 pm: Edit

MA
East Coast Rovers have 3.8 r&p for $395 per axel.
Go to resources click on vendors

Michael B

By slider on Tuesday, July 10, 2001 - 01:10 am: Edit

Has anyone hardened (heat-treated) they're own driveshafts or axles???

By Ron on Tuesday, July 10, 2001 - 04:29 am: Edit

People have kyro frozen them. DOn't think you could temper them too well with heat.

Ron

By Redsrover (Redsrover) on Tuesday, July 10, 2001 - 01:27 pm: Edit

How will stock gears and 235 85 BFG Mud Terrains work together? Mostly in town and trail riding for this rig. thanks

Ron

By Kyle Van Tassel (Kyle) on Tuesday, July 10, 2001 - 01:39 pm: Edit

It aint bad but the power loss is noticable. If you are going to that size from 245 it naturally wont be that bad. From stock to that size is a pretty big hit though..

Kyle

By Alex Schubow (Alex) on Tuesday, July 10, 2001 - 02:40 pm: Edit

I ran 235/85s with stock gears for about a year. I didn't notice much of a power difference from stock. Descending steep hills was a bit more exciting, but not too bad.

Having said that, when I put in the 4.1s there was definitely a noticeable power increase, and crawling speed is also noticeably better.

Maybe it's because the loss in gearing going from stock tires to 235s (10% difference) is not has drastic as the gear change (16% difference).

Alex

By Redsrover (Redsrover) on Tuesday, July 10, 2001 - 04:39 pm: Edit

Thanks for the info. I would be going from 245 75 to 235 85 with stock gears. Where's a good source for 4.10s and is fitting them a job for the average guy with hand tools and ramps?

What's the largest tire size suggested for stock gears??

Ron

By Alex Schubow (Alex) on Tuesday, July 10, 2001 - 05:13 pm: Edit

If you have an auto, I doubt you will notice a difference in the gearing now. Do get the 4.1s if you can though, you will love them.

If you just buy the gears, you have to know how to set up a differential, etc. to install. Since I've never done that before, I ordered complete third members (with exchange of my old ones) from Great Basin Rovers. Installing those is not complicated at all.

As far as the largest size for stock gears, I don't think I would go over 32" or so...

Alex

By Ho Chung (Ho) on Tuesday, July 10, 2001 - 07:57 pm: Edit

ron,

i've gone from 245/75 to 235/85 on stock gears.
didnt' notice much, but the long up hills and the rockies driving was just not working well.

went with the 4.10 gears and all i can say is that i should have done it sooner.

it's about 2 DSU but it's a very well spent DSU.

good luck

By Leslie on Wednesday, July 11, 2001 - 03:56 am: Edit

DSU?

By Rob Davison (Pokerob) on Wednesday, July 11, 2001 - 04:11 am: Edit

one (DSU) discovery spending unit = $500.. think about it.

rd

By Kristian on Wednesday, July 11, 2001 - 09:48 am: Edit

With the current market trends, the DSU has dropped slightly in value. Check today's Journal; it'll have the info...

By ryan on Wednesday, July 11, 2001 - 11:00 am: Edit

huh? If a D-90 runs 265/75-16 tires with 3.54 gearing, couldn't a disco do it without breaking stuff? 235/85-16 shouldn't be a problem on a disco, right??

By nadim on Wednesday, July 11, 2001 - 11:02 am: Edit

ryan, i think the gearbox on the D-90 has different ratios and therefore lives with the taller tires...plus, the D-90 is considerably lighter...
i hope i am wrong though, coz this does not sound logical to me...

By Ron on Wednesday, July 11, 2001 - 11:03 am: Edit

Its the T-box ratio. You can switch around the T-box to give you what you want


Ron

By nadim on Wednesday, July 11, 2001 - 11:08 am: Edit

Ron...

that's it...i have 4.7s already, so maybe when i get those nice 33s/34s/35s i'll put in the lower t-box ratios?
we'll see

By willis on Thursday, July 12, 2001 - 03:40 am: Edit

...still confused about the DSU??...

By Andrew Vick (Afv) on Thursday, July 12, 2001 - 05:24 am: Edit

It's kind of like going to Home Depot, Costco etc. and never being able to get out of there without spending less than $200. In the previously stated example, nothing for a Disco costs less than 1 DSU (or $500). Most things are 2 DSU's, and a few are 3 DSU's.

Capiche?

By ButchS on Monday, July 16, 2001 - 06:47 pm: Edit

31 TSL swampers with 3.54 95 Disco is no good above 75 mph. Feels heavy and slow. What's a good gear ratio for tires using 265 75s or 265 70s?

By Crackhead Mike, according to Backyard Kyle on Monday, July 16, 2001 - 07:30 pm: Edit

Too many DSUs and it's definition changes to Divorce Situation Unfolding!