[svsantosh]

Originally Posted by star_aqua

Hi Santosh, First of all, the engine is slightly running rich and what is the diff ratio for your 340? isn't it 5.38? if it is, the best FE you could get is at around 50kmph assuming 30" dia tyre and DP engine running at 2000rpm which produces peak torque without emitting black smoke. if you cruise more than 50kmph, then the FE drops. If you want more mileage and better cruising speed, then you may have to reduce the diff ratio.

Hi Vijay - Yes - its stock 5.38. And the tyre is 215/15/75. I like the ratio - its superb in OTR condition.

[DesertKing]

Originally Posted by star_aqua

Hi Santosh, First of all, the engine is slightly running rich and what is the diff ratio for your 340? isn't it 5.38? if it is, the best FE you could get is at around 50kmph assuming 30" dia tyre and DP engine running at 2000rpm which produces peak torque without emitting black smoke. if you cruise more than 50kmph, then the FE drops. If you want more mileage and better cruising speed, then you may have to reduce the diff ratio.

This is some very new information to me... Thanks. Can you pls guess (I am not sure if you can calculate the exact) the speed for best FE for my Jeep.. I have XD3P engine with 31 inch tall tyres and 4.27 diff ratio.

[star_aqua]

Originally Posted by DesertKing

This is some very new information to me... Thanks. Can you pls guess (I am not sure if you can calculate the exact) the speed for best FE for my Jeep.. I have XD3P engine with 31 inch tall tyres and 4.27 diff ratio.

Hi Naren, its a simple calculation based on the peak torque rpm and the powertrain gear ratios. i guess you have retained KMT 90. a comfortable cruising at 70kmph would be the speed for the best FE for your JEEP.

[DesertKing]

Originally Posted by star_aqua

Hi Naren, its a simple calculation based on the peak torque rpm and the powertrain gear ratios. i guess you have retained KMT 90. a comfortable cruising at 70kmph would be the speed for the best FE for your JEEP.

Thanks Star_Aqua. Before somebody else point it out about the aerodynamics, I would like to mention that I know that it is not the only max RPM range for torque which effect the FE but saveral other factors also.

[star_aqua]

Originally Posted by DesertKing

Thanks Star_Aqua. Before somebody else point it out about the aerodynamics, I would like to mention that I know that it is not the only max RPM range for torque which effect the FE but saveral other factors also.

Yes Naren, I agree with you.
I think you did not get what I meant in my previous posts. I am not talking about how to convert a jeep into a super car or what modifications(other than powertrain) needs to be done for gaining max FE. I was just trying to convey what should be the cruising speed for a JEEP to gain the max FE with its current dynamics. Just a driving tips. And i did mention "comfortable cruising at 70kmph" which i meant the engine feeling comfort to drive the vehicle at that speed and not the driver.

[Sha]

Originally Posted by star_aqua

Hi Naren, its a simple calculation based on the peak torque rpm and the powertrain gear ratios. i guess you have retained KMT 90. a comfortable cruising at 70kmph would be the speed for the best FE for your JEEP.

Now i know why your tractor goes slow and slow.

[princezahed]

Originally Posted by kittigadu

umm,
Looks like the same problem as in mine. Last week i changed the engine oil and the problem seems to have disappeared. suddenly yesterday the problem returned back. The shuddering, jerking etc is not consistent. It happens some times and doesn't when you bring someone to show it to. Star Aqua suggested a series of steps last week when we saw the problem. My mech said that one of the cylinder is not firing due to a blocked nozzle and thats the reason for the shudder. Have given it to get the nozzles cleaned. He said he will be removing them and take them to some pump house.

shall let you know once this nozzle thing is done.

Regards,
Krishna.

Hey krishna please let me know if your problem is solved after your mech cleans it. Also where is your mechanic situated? All these months I got my jeep repaired in Coorg but now iam in bangalore and find good jeep mechanics hard to come by.

[Samurai]

Built a Jeep for my son today, check it out here: https://www.team-bhp.com/forum/shift...eep-build.html

[Samurai]

For almost a year now, I have been looking to improve the reliability of the silent bush shackle system. I first realised the danger in Munnar, when my notice was drawn to the shackle nut on the morning of MGE. It was just about fall off.

Later when I discussed with the Mahindra workshop about making this fall-proof, they used two nuts tighened against eachother to secure it. When I asked whether grease type shackle can be used, I was told that is not an option. So I learnt live with it.

However, when I switched over to CF leafs, the same silent bush shackle system created further complication. The shackle was holding the leaf too tight resisting the free movement of the CF leaf.



The first reply got when I posted this problem was from star_aqua.

Originally Posted by Samurai

This topic has come up once before when I lost the shackle nut. I asked the Mahindra workshop to change into grease type shackle with nipple. I was told it is not available of this end of the leaf.

Originally Posted by star_aqua

How come?? They would have not had this part with them. grease type shackle kit is available in all local automobile spare part shops.

Anyway, there was no point going back to Mahindra workshop since I knew they had ruled out the possibility.

After thinking over various possibilities, I finally decided to consult a local master mechanic as suggested by Udupi BHPian Sachin Karkera. After that, this happens:

Originally Posted by Samurai

However, there is light at the end of the tunnel. Today I visited a master mechanic in Udupi to resolve the problem in fitting the CF leaf properly. When I went there, the plan was to make a custom shackle bush to relieve the pinching by the shackle plates. However, star_aqua's suggestion of using a grease shackle kit was still lingering in my mind. The Mahindra workshop had ruled out the possibility saying grease tyre shackle kit is not available for bumper end of the leaf springs. Apparently it is not an OE design, so Mahindra workshop won't deviate from it.

Today I brought up the same issue with the master Mechanic. He said it should be possible, but he wanted to see the existing shackle bush before commenting. After all, he has never seen a CF leaf before this. So we jacked up the vehicle, and removed the leaf end and the shackle bush. It was the exact size as the grease type shackle kit. I just wanted to break into a dance right away...

So we quickly went to a local auto shop and bought 4 shackle assembly kit. I stayed around to see one of them being fitted. It fits gloriously, and now the CF leaf is able to move very freely, without any hitch.

I am reposting all this history here because I wanted to share the clear improvement of grease type shackle over the silent bush type.

Next four shots are taken via mobile phone, the last two using P&S. So pardon the quality.

Check this baby out... it is lightyears ahead of the older design.



The bolt is hallow to hold the grease. The grease nipple will cover these holes.



You can see the hole on the left that will enable the grease to flow out and lubricate the shackle cylinder. The hole on the right will accept a pin that will ensure that the nut won't fall out.



The shackle plate is grooved, this will let you adjust the distance between two shackle plate to enable the leaf to move smoothly, even when the outside nuts are fully tightened.



Here is the installed shot of grease type shackle. Now the CF leaf can move smoothly. The shackle kit also came with metal washers for both sides.



The shackle on the front.



The price of grease type shackle kit which includes washers and nipples, is just Rs.276 only. So I replaced all four shackles, now the Jeep has 8 more grease nipples.

Now this is making me wonder. Why is Mahindra not making these available for Jeeps through their workshops? Why are they still using silent bush over grease type?

[svsantosh]

This was a good and needed Mod. congrats - How is the CFL ride now?

PS - Do you already have Greased type pin at the other 4 end's of the leafs? That would make it 12 nipples for the Leaves alone.

[DKG]

Sharath I just replaced all the springs on my CJ3B with a new set. When I enquired if I should stick with the grease system vis-a-vis the silent block bush there was a unanimous vote for the grease system on grounds of freer movement. So I too opted for a new grease system shackle set as was there originally

[fk7]

Hi,

I do have a query. Can this be bought locally or needs to be custom made? And if custom made, can this be further enhanced to produce a shackle lift?

Firoz

[Samurai]

It can be bought in any auto-parts shop. Shackle lift is bad for the stability of the vehicle, better to avoid it.

[BaCkSeAtDrIVeR]

Originally Posted by Samurai

Now this is making me wonder. Why is Mahindra not making these available for Jeeps through their workshops? Why are they still using silent bush over grease type?

From my experience of maintaining some commercial vehicles - just one answer - these vehicles go to the street side (literally) greaser. You cannot miss them at the lorry parking places. They will be standing besides their usually 20 liter grease gun / barells. If these guys miss out on greasing even one nipple, you can look forward to spending a huge sum on replacing that part very shortly.

Edit:- IIRC, there is a bush, which goes into the main leaf; does Rs. 276 includes the bush? The bush is gun metal or brass?

[Samurai]

Originally Posted by svsantosh

This was a good and needed Mod. congrats - How is the CFL ride now?

I haven't done much driving after it. But the master mechanic who took it for trial said it has very little jump at the back compared to other Jeeps.

Originally Posted by svsantosh

PS - Do you already have Greased type pin at the other 4 end's of the leafs? That would make it 12 nipples for the Leaves alone.

Yeah, those have grease type pin right from the factory.

Originally Posted by BaCkSeAtDrIVeR

If these guys miss out on greasing even one nipple, you can look forward to spending a huge sum on replacing that part very shortly.

The Jeeps already have lot of grease nipples, so 8 more shouldn't be an issues. Besides, these will be the most visible/accessible ones and can be replaced cheaply.

Originally Posted by BaCkSeAtDrIVeR

Edit:- IIRC, there is a bush, which goes into the main leaf; does Rs. 276 includes the bush? The bush is gun metal or brass?

The first photo shows the bush, looks like brass going by the color. Yes, it is part of the kit. The Rs.276/- kit consisted of 2 shackle plates, 2 bolts, 2 nuts, 2 brass bushes, 2 washers, 2 nipples, and 2 pins to hold the nuts.