Quote:
Originally Posted by shivshanker Having bought a Thar, my vehcile is hardly run for 400 kms and I am having serious problems with the gear throw from standstill. Also, while shifting from second to third there is a the gear grinding noise, now this disappears if I take maybe 10-15 seconds more to shift the lever from second to third and it is butter smooth. For the above two problems, I took my vehicle and hence took it to the Mahindra Authorized Service Station, the service manager has come with some interesting observations:
1. Initial feedback from the service advisor was "Sir, pressure plate and clutch plates need to be replaced" after throwing a bit of weight around, the service manager walks in.
2. The additional layer of carpeting installed and the rubber mat on top is preventing the clutch lever from travelling the full distance and hence this problem. The Carpet was installed by Mahindra Customization during the Hard top installation, I hope that Mahindra customization does all hardtops based on similar specifications and simply cannot accept this as a probable cause.
3. Since the car was standing still for over 4 weeks, the cork material on the clutch plates would have been stuck to the pressure plates and hence there is a problem with the clutch assembly.
4. As a first step, they have bled the gear box yesterday to take out any air inside.
5. I want a permanent solution. |
Dear Shivshanker - hello once again. My reply for each point from 1 to 5 is as follows:
1. Ridiculous! This statement is not correct. This is normally the first line of defence, they get reimbursed for warranty and you are out of their hair for some days, that's all! Therefore, HaHaHa - 1.
2. Just remove all the carpets and take a drive, this will not solve the problem because if this was true, all gears would be hard to shift! Therefore, HaHaHa - 2.
3. Clutch plate has something better than "cork material" in it! Even if the vehicle stands for much more than 1 month, this should not happen. Those days when this used to happen are long gone. Therefore, HaHaHa - 3.
4. Let me start with HaHaHa - 4, because this is the most ridiculous thing I have ever heard. The transmission has a breather which keeps the pressure inside same as atmospheric pressure. There is nothing like "transmission bleeding"!
5. For permanent solution, please read below.
Observations 1 to 4 clearly indicate total lack of root cause analytical ability / customer handling capability. Smiley is definitely called for, Saar! Enjoy!

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The broadbased reply is as follows:
The synchronizers provided inside the transmission work to match the speed of the driver and the driven modules of each gear before the sleeve slides into place to provide the drive. In order to match the speed, the modules have to either "speed up" or "slow down" as the case may be. Anything which moves has inertia. The synchro-cone's job is to control this inertia and bring the rpm to the required value
within the normal operating time of the particular gearshift. You are finding this operating time high, that too only in the first gear. Please remember that as the first gear gives maximum reduction ratio, the inertia of the first gear is more as this gear is physically bigger than any other gear. In the NGT530R, this "time-to-inertia-control" is somewhere near the limit in the first gear, so you will sometimes feel this phenomenon. As you move up the gears, you will not feel this phenomenon.
The reply to your specific sentence is as follows:
I quote your sentence: "1. I have to first shift to second, release the clutch slightly so that the vehicle moves an inch or so and then engage either reverse of first. 2. This problem is more prominent after a cold start".
1. No gear will ever engage if the dog teeth of the driver gear, the synchronizer and the driven sleeve do not line up perfectly. This is how all synchromesh transmissions work all over the world. You just drive forward by an inch or so till the modules slot into place, you must prevent crashing, which you can do by gently carrying out this manoeuvre. There is nothing wrong in doing this, but somebody needs to explain this to you in plain and simple language. I hope I have done so.
2. The viscocity of the transmission oil (as also its quantity) results in fluid friction which causes this temperature related phenomenon for a short distance, usually less than 2 kms, only in winter. As the transmission runs, it generates heat output which sorts out this behavior. A lot of work in the tribology area is conducted to minimize this phenomenon.
The core competence of the service advisor lies in actually driving the vehicle in the modes that the customer complains about, have the "Vehicle Behavioral Feel" in him to be able to access whether the issue actually exists or not and then to correct the vehicle if the issue exists or to guide the customer properly till he is satisfied by the response. This activity must be conducted on your vehicle to arrive at the correct response. In my opinion, if the service advisor is not able to conduct this activity, I suggest you do so yourself, nothing wrong there. You will get the correct answer.
"Please don't open anything, this is for your own good"! Please spare your vehicle from the clutches of the "sarvaguna sampanna / sarvavyapi" (ever present) "grease monkeys"!
Best of luck!
Best regards,
Behram Dhabhar