Topic: best gearing options for a tj auto (Read 11409 times)

Bubba · « **on:** January 17, 2010, 05:33:50 PM »

opinions please would be very helpful

Dodster · « **Reply #1 on:** January 17, 2010, 06:19:02 PM »

This is how I understand it.. (If Ive got the right meaning of the question)
31" tyres 3.73 gears
33" tyres 4.11 gears
35" tyres 4.56 gears,
33's on 4.11 gears was just right, 35's on 4.11's are just ok, like running 31's on stock gears but 4.56 would be much better.

Bubba · « **Reply #2 on:** January 17, 2010, 06:36:01 PM »

sweet that was my understanding
i think 4.11 and true track is the the sweetest harmless way of gaining extra traction....?

Dodster · « **Reply #3 on:** January 17, 2010, 07:14:40 PM »

IMO definately.. a great compromise between full lockers and none..no fuss no extras, dont know its there till you want it and not too much strain on shafts etc

gazjeep · « **Reply #4 on:** January 17, 2010, 07:15:59 PM »

Bubba you beat me to asking the question only cause I had to walk the dog

Dodster, glad you popped up, were your ears burning this afternoon ? You are the only person I know who has been down this route with an auto

Just a pinch more detail for folks, as the rear diff pinion bearing is protesting, it would look to be the ideal opportunity to think about a re-gear with true trac limited slip diffs front & rear on our 98 TJ.
Not going to go down the locker route as rightly or wrongly I dont want to overstress the otherwise standard driveline.

Its a 3 speed auto which has always been entertaining going down hill to say the least, made worse by the fitting of 31's. I appreciate that as it is an auto its never going to have the engine braking of a manual but want to improve it to a less bum twitching level.

Think I am going to stick to 31's so I dont have to go down the swing out spare carrier route, so would 4.10 be enough or 4.56 be the best / too much ?

Currently doing 60 mph its doing about 2100 rpm. Anyone know what fitting 4.10 or 4.56 would do to this ?

Rednex seems to be the favorite place (do they have a website ?) at the mo to have the work done but any experiences of other places would be appreciated.

gazjeep · « **Reply #5 on:** January 17, 2010, 07:18:50 PM »

Hiya Phil

Was suprised to find out today that the rear diff on ours is an open diff, thought all TJ's had a LSD as standard

Just founf this, 4.10 seems to be about right then yeh ??

http://jeephorizons.com/tech/rpmchart.html

Dodster · « **Reply #6 on:** January 17, 2010, 07:29:32 PM »

I'm not sure if mik is still about but i had a similar conversation with him.
4.56 were recommended for 35's unless I liked rockcrawling in which case they would be good for 33's.
4.56 would be too much for 31's..IMHO.

Hey gaz, I dint know that about the diffs being open I just thought mine was shot..

Bubba · « **Reply #7 on:** January 17, 2010, 07:32:08 PM »

i think 4.11 is where the sweet spots at but i is a retard

isle of man · « **Reply #8 on:** January 17, 2010, 07:32:20 PM »

It's prudent to stretch a gear with Automatic as opposed to going deeper on manual.

gazjeep · « **Reply #9 on:** January 17, 2010, 08:11:37 PM »

Phil

I was surprised too, but I am reliably told by Kev that there was no LSD set up on ours when he had the pumpkin off today

Do you think Rednex is no more ?

Peter

Pardon my mechanical numptiness, are you saying go with 4.10 for the auto or 4.56 ?

Dodster · « **Reply #10 on:** January 17, 2010, 08:36:58 PM »

I heard, maybe a rumour, that Mik had hung his spanners up..but rednex could live on with others at the helm..? Worth a phone call tmrw.

Bubba · « **Reply #11 on:** January 17, 2010, 08:55:21 PM »

that was my understanding

isle of man · « **Reply #12 on:** January 17, 2010, 09:05:25 PM »

MIK is now in Portugal I believe with his KTM Enduro business.

Flash don't overcook the gearing it will rev it's brains out and drink the petrol!!!!!

PtP · « **Reply #13 on:** January 17, 2010, 09:52:12 PM »

Quote from: gazjeep on January 17, 2010, 07:15:59 PM

Think I am going to stick to 31's so I dont have to go down the swing out spare carrier route, ...........

Have you seen this adaptor from LLama4x4?

http://www.llama4x4.com/page7.htm

Bishops Finger · « **Reply #14 on:** January 17, 2010, 10:18:36 PM »

Please don't tell me thats an adapter for a rear mounted 33...

Bubba · « **Reply #15 on:** January 17, 2010, 10:26:23 PM »

no its a stileto for a horse

wildwood · « **Reply #16 on:** January 17, 2010, 10:46:38 PM »

Well I did the math (and I still think that should have and S on the end)
The calculator says that 4.10 is the gearing for 33s and 4,56 is for 35s

So..... many years ago I regeared for 33s with 4.56 and I loved it with a manual and I could travel using 4th and 5 th at most times around town and roundabouts etc. knowing I have gone deeper with the gears than necessary then I changed to 35s and this is the right tyre for the right gearing? OH NO! you are now in the same territory as a standard YJ or TJ on 31s with standard gearing IE 5th is just that bit too much of an overdrive! Its the weight and I guess the lack of aerodynamics.... OK forget that its the weight.... If you want sprightly performance on 35s go 4.88.... its the deepest you can go on a Dana30 front anyway

gazjeep · « **Reply #17 on:** January 18, 2010, 08:30:35 AM »

Right then, In summary, 4.10 gearing for 31's & true trac limited slip diffs front & rear it is then.

Now then, where can I get this done ?

All options considered, as we are in Worcester, somewhere midlands based would be prefereable but not essential.

Contact details would be mighty helpful & I can then start making some phone calls to spend some monies

JamesH · « **Reply #18 on:** January 18, 2010, 08:37:02 AM »

You beat me to it but below is the reply I was typing while you posted:

I have 33s with 4.10 gearing on an XJ auto and it's pretty good on everything except steep descents. I've always been able to control it using brakes carefully but it's not the text book way to drive. In mud it's probabbly better than deeper gears because it gets the wheel speed up.

I loved 4.10 gearing with 31s though and am with Bubba that it's a real sweet spot. My current setup struggles on some of the long, steep motorway inclines in France when I'm loaded up with 2 weeks worth of camping and holiday gear.

Like Wildwood said, it's not just the tyre diameter increase but the extra weight and drag of a bigger vehicle with skid plates etc. I'd like 4.88 for 33/35s really, I could cope with keeping motorway speed down a bit and the 4.0 doesn't seem to mind revving a bit anyway.

Dodster · « **Reply #19 on:** January 18, 2010, 08:42:11 AM »

Coventry Transmissions
St Agathas Road
Coventry
CV2 4DX West Midlands

Tel: 024 76635054

Deep pockets are required apparently

PtP · « **Reply #20 on:** January 18, 2010, 07:14:58 PM »

I've heard good reports via the Landcruiser forum about:

Midland Transmission Services Ltd
Midland House
Hayes Lane
Lye
Stourbridge
West Midlands
DY9 8RD
sales@gearbox-mts.com
Telephone: 01384 424823
Fax: 01384 422819
http://www.gearbox-mts.com/axels-and-differentials.html

One of the guys on the LC forum recently had a re-gear done by them and was pleased with the result. The LC guy supplied all the parts though.

gazjeep · « **Reply #21 on:** January 18, 2010, 07:45:46 PM »

Cheers Pete,

Have dropped em an e-mail.

Had a quote already from Offroad MDG

If all the same as that one, operation re-gear has been black balled by SWMBO, fingers crossed we can get it done a good bit cheaper

Not heard back from EDM yet.

Will try & ring the place in Coventry tomorrow that Phil suggested, always assuming I chatge my sodding mobile DOH

Bishops Finger · « **Reply #22 on:** January 18, 2010, 08:42:29 PM »

Sell it and buy a JK??

scrw · « **Reply #23 on:** January 18, 2010, 09:21:42 PM »

BTW Gaz, you can install a manual switch to hold the torque converter lockup for your downhill stuff, have a link somewhere detailing it.

wildwood · « **Reply #24 on:** January 18, 2010, 10:46:37 PM »

Try Steve at FTE. His bloke has been doing axles for Santa Pod Guys for decades and now just does stuff for Steve for cash as he is 'retired' he's done 4 axles for me and all have been great. Only down side is he will only work on the axles off the vehicle. So you have to strip, ship, collect and reassemble....worth it tho save you a packet.....unlike other people who also have ''Initials"

NNUC Never Knowingly Undercharged.... Just my opinion of course.

Author Topic: best gearing options for a tj auto (Read 11409 times)

Dodster

Dodster

Dodster

Dodster

Bishops Finger

Dodster

Bishops Finger

scrw