[GTO]

A great deal of suggestions and analysis has been done here, but I would suggest that you simply go +1 on the tire size and see how your jeep works.

Behram & Arka insist that we've gone all out to get reliability onto my Jeep, and that I shouldn't mess around with the suspension at the moment. I'm thinking of purely bolt-on tried & tested methods for now.

Yup, starting with the tyres. What size are you running on your 340, any mods to accomodate them and the pros / cons of a large tyre size?

[trammway]

Originally Posted by GTO

Behram & Arka insist that we've gone all out to get reliability onto my Jeep, and that I shouldn't mess around with the suspension at the moment. I'm thinking of purely bolt-on tried & tested methods for now.

Yup, starting with the tyres. What size are you running on your 340, any mods to accommodate them and the pros / cons of a large tyre size?

I'm working on the same direction as you are thinking with your Classic.

I did try with Sandgrip tyres in my Classic and I was really not confident in having it in the Jeep. Looks like 31" height on the tyre may turn disastrous for our jeep. What I'm thinking is to go for 30" height, BF Goodrich is what I'm hearing more frequently.

The current 215/75 R15 is about 28" height and adding 2" more will make a lots of difference. I think that is the direction I'm planning to move now. May be a 235/75 R16 (Look 16" rim) shourt result in 30" tyres. I hope we can get some what similar to this configuration.

Looking out for options to import steel rims from USA now, I'm not ok to alloys hence I'm attempting to import nagative offset steel rims. If everything fails, I will settle for Alloys.

The ones like listed on this page:
Raceline Wheels - Wheel Specifications

[trammway]

One more question on this same subject, What are the alternate suspension lift kits that we can use in CL340 DP- Classic that are available in INDIA.

All I can see is that in USA there are many options right from 1" upgrade to 4" (See the link below)

Vintage Willys & Jeep CJ Suspension Lift Kits


what about the availability in India ? Is there any on the shelve options so we can avoid modifications on the Jeep chassis ?

[GTO]

What are the alternate suspension lift kits that we can use in CL340 DP- Classic that are available in INDIA.

Options (including parts from the 550) available in India are listed by Arka. I guess the rest have to be imported. We have to understand that these Jeeps sold in very limited numbers, and even fewer of them are on the roads today, hence Indian aftermarket support will be next to zero.

[RedMM340]

Originally Posted by GTO

Behram & Arka insist that we've gone all out to get reliability onto my Jeep, and that I shouldn't mess around with the suspension at the moment. I'm thinking of purely bolt-on tried & tested methods for now.

Yup, starting with the tyres. What size are you running on your 340, any mods to accomodate them and the pros / cons of a large tyre size?

I am running 30 x 9.5 R15 tires, which work well for most off-road situations. A 31 in tire should be more than enough for off-road ground clearance for 99.9% of situations, while not causing any on-road problems. In fact the 31x10.5 R15 is probably the most popular size tire to give all around on and off road performance with adequate floatation for mud and sand.

You should have enough power with your new 2.5L engine to run either a 30 or 31 inch tire without the need to re-gear. You may have to do a very slight modification to accomodate the 31 inch tire such as the shackle modification mentioned by Behram. Just drop the 31 inchers in and run the jeep to see if there is any tire rub. You might get a little rub on your leaf spring on the front tires at full turn due to the increased diameter which can by fixed by adjusting the offset.

Only downside to the bigger tire is a little decrease in braking perfomance, which is not a really big deal. Just use a top quality tire like Michelin or BFG and keep your brakes in perfect condition to compensate.

[4x4addict]

Originally Posted by RedMM340

I am running 30 x 9.5 R15 tires, which work well for most off-road situations.

Is this size available in India? Which brand did you get?

[Kandisa]

Originally Posted by 4x4addict

Is this size available in India? Which brand did you get?

I too have recently procured the same size for my jeep. Perfect size IMHO without loading the steering too much.

[trammway]

Originally Posted by Kandisa

I too have recently procured the same size for my jeep. Perfect size IMHO without loading the steering too much.

It would be nice to see one of you people post a picture of your Jeep with the tyre in question.

Also please let us all know what brand the tyre marketed? and ofcourse price paid

[RedMM340]

Originally Posted by 4x4addict

Is this size available in India? Which brand did you get?

I am running BFG Mud terrains that I imported. Not sure if it is available here through Michelin India. The 30 inch is a bit small for off roading in my opinion, and I would recommend the 31 inch as the ideal size.

Michelin does sell a 31 x 10.5 15 All Terrain, which is a great tire.

[GTO]

Originally Posted by trammway

Looks like 31" height on the tyre may turn disastrous for our jeep.

The current 215/75 R15 is about 28" height and adding 2" more will make a lots of difference

Won't the effective gain in height (from a 28" -> 30") be 1 inch?

Originally Posted by RedMM340

A 31 in tire should be more than enough for off-road ground clearance for 99.9% of situations, while not causing any on-road problems. In fact the 31x10.5 R15 is probably the most popular size tire to give all around on and off road performance with adequate floatation for mud and sand.

Thanks. Just what Arka has recommended. I'm going to install these on the Classic real soon. And then look at other (simple) modifications. Based on Behram's & Arka's advice, I'm off SPoA for the time being.

Only downside to the bigger tire is a little decrease in braking perfomance, which is not a really big deal.

Hey, I got disc brakes

Originally Posted by RedMM340

Michelin does sell a 31 x 10.5 15 All Terrain, which is a great tire.

I am a fan of Michelin's tyres. Will check out.

[Samurai]

GTO, I am a little skeptical about moving to 31x10.5 tyres on a 340, and this is why.

Originally Posted by Samurai

Initially the trail was full of sand and tall grass. We were after all riding an almost dry river bed which would be full of water in the monsoons. Initially the Jeep behaved as if it was drunk. Even though I was following Prithvi’s Gypsy, I kept going out of track on every side. After couple of minutes of this I stopped and wondered about it. It can’t be a steering issue, I had driven this Jeep just this morning in city traffic. I continued further keeping a very critical eye on the Jeep handling. Soon I figured it out, the steering simply wasn’t twisting back after every turn. I couldn’t trust the steering to swing back even a little on this sandy trail. So I resorted to turning back the steering every time after a turn. It was because of the huge 31x10.5 tyres.

These were Michelin LTX by the way.

[DKG]

Some have suggested a spring over axle mod for increasing ground clearance. Considering the GC is technically the distance between the ground and the lowest part of the suspension I fail to see how a SPOA increases GC. I see it only increasing the body/chassis to ground clearance. Could someone please clarify?

To me the only way to increase GC is to increase tyre diameter. If its your diffs bottoming out often then larger tyres is the only option to me. If its your body/chassis getting grounded often then larger tyres followed by spoa is the eventual mod for better clearance.

Someone please correct me if I got that wrong

[Alfa_Kilo]

Originally Posted by Samurai

GTO, I am a little skeptical about moving to 31x10.5 tyres on a 340, and this is why.

These were Michelin LTX by the way.

The steering may be reluctant to self center if the tyres were installed on rims with high negative offset.

[DKG]

GTO my recommendation is not to mess too much with ride height. While you may be wanting to do so for the sake of clearing rocks a taller car will compromise your centre of gravity and increase the tendency to roll over. Often when offroad you would be tackling slopes sideways too. Now visualise what tampered ride height would do to vehicle stability in such cases.

Further we all are doing a considerable amount of highway driving at speeds easily in the range of 60-80 kmph. A taller car would be more unstable and unsafe.

Unless you are increasing wheelbase and track please avoid increasing ride height. It affects the dynamic handling characteristics of the car, even offroad. I'm sure the designers didn't build the Jeep with anything other than offroad prowess in mind. Surely if the car could handle a taller stance and stay safe in all offroad conditions they would have designed it in. After all cars rode on size 33 tyres in the 1920's !!

My suggestion is if at all you do anything stick to what Mr. Dhabhar recommends as he should know what's permissible within limits of safety. An experiment based on half knowledge can be dangerous

BTW my underlying concern on this particular subject is the compromise of our safety

[DHABHAR.BEHRAM]

Dear DKG - thank you for clearly reinforcing what I have been saying all along. You just cannot play around with reliability. I have seen a dime a dozen garages just waiting to take away people's hard earned money and sopil their cars at the same time.

Dear GTO - As you want more ground clearance, I think that you may be able to get away by using army tyres on an army wheel rim having 139.7mm pcd (the one on the "old" army MM540). Tyre performance on road and tyre NVH will be bad, though. I am attaching Mr.Fazal Ali Adil's vehicle photograph showing the mounting. I am working out the result with the formula with 5.38 and let's see what happens. I will give you the resultant shortly.

Best regards,

Behram Dhabhar