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transmission weird problems

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  #11  
Old 10-01-2012, 04:23 PM
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Yes, I described it exactly because..
These Rovers are made identical.
The ZF transmissions are identical.

What goes wrong and wears out goes wrong.

You will probably only affect it positively if you take the torque converter out and put in a new one.


OK, there is some good stuff

I just found

Such a symptom is often a torque converter shudder. A torque converter shudder is a brief shake or shudder in the vehicle when the torque converter goes to “lock up.” Very often this problem is mis-diagnosed and sometimes transmissions are needlessly rebuilt as a result.
One way to identify a torque converter shudder is lightly touching the brake pedal, while carefully maintaining vehicle speed with the other foot. If the shudder immediately stops, with brake application, the problem is likely the torque converter clutch. When brake application is seen most torque converter clutches will be released. A trained transmission service technician can also test for torque converter lockup using a vehicle scan tool, specific for the application.
How a torque converter lockup works

The torque converter is a coupling between the engine and transmission of the vehicle. The purpose is to allow the vehicle to come to a stop, with the engine running. From this perspective, it acts much like an automatic clutch.

Torque converters work by transferring power, through fluid motion. An easy way to understand might be to consider two desk fans. One connected to power and turned on, the other unplugged. Motion of air, coming from the running fan, can make the blades in the non-running fan turn. A torque converter works similarly. Internal blades, attached to the converter housing and bolted to the engine flywheel, move transmission fluid. The motion of this fluid causes other blades, attached to the transmission, to turn. This drives the vehicle and at idle, allows the engine to run with the vehicle not moving.

In modern vehicles, a clutch is also included in the torque converter. Because there is slight slippage when driving, fuel mileage suffers. A clutch inside the converter “locks up” when slipping is no longer needed. This transfers more of the available power and helps fuel mileage. This clutch requires very specific lubricants in the transmission fluid to work properly.
What causes torque converter clutch problems?


Torque converter clutch lubrication is one reason there are so many automatic transmission fluids (ATF) on the market. Without the additives in these fluids the clutch may chatter when it engages, causing the shudder sensation. In time the clutch may be damaged and material from the clutch can ruin the automatic transmission.
Using improper fluid, when flushing a transmission can cause a torque converter shudder among other problems. This is a particular problem with Honda and Ford vehicles. Time, heat and mileage cause the additives in automatic transmission fluid to become depleted. Without these additives, clutches may chatter and wear. Depleted fluid can also cause gasket and seal shrinkage, resulting in leaks. Ford rear-wheel drive vehicles have had a good deal of trouble with this.
Preventing problems with a torque converter shudder

Prevention and even repair is often as simple as a proper transmission service. In a proper transmission service, the fluid is drained and the transmission pan is removed. This allows the technician to inspect the transmission for wear and broken parts. At this step small problems can be easily corrected, preventing major breakdowns.

The bolts on the transmission valve body should also be tightened to the specified torque. As the valve body gasket shrinks, from heat and depleted fluid, cross-leaks can develop among the passages. This can cause transmission failure and sometimes be prevented by this step. The transmission filter is then replaced, the pan installed and the transmission filled with the proper fluid. Replacing the filter is key. Restricted transmission filters lower internal pressure and can destroy a transmission very quickly.
A proper transmission service is very different than a transmission flush. With a transmission flush, clean fluid is circulated through the transmission. The filter is not addressed and the internal components are not inspected nor valve body bolts tightened.
Bigger automatic transmission problems

If excessive material is found in the transmission pan or if the shudder persists after a proper service, the torque converter may have to be replaced. Continuing to drive with the shudder can result in automatic transmission failure. When this occurs the transmission will need to be repaired, replaced or rebuilt. Proper automatic transmission service, at regular intervals are the best prevention. Let the experts at AGCO properly service your transmission. AGCO, it’s the way to go.
 
  #12  
Old 10-01-2012, 04:28 PM
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Ah, that's a dumb article I put in above.
We don't have a lockup problem.
This problem is from start off the line.


Here is a guy doing the stall test

 
  #13  
Old 10-01-2012, 04:34 PM
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  1. Shudder Symptoms

    • Torque converter shudder fells like a slight to heavy vibration in the transmission, and is usually accompanied by an interruption in power transfer. It generally occurs at part throttle and light acceleration, between 15 and 50 miles per hour, just before the shift to one of the top gears where the converter reaches "lock-up." Since it is temperature-related, it tends to happen on hot days, after idling in traffic for long periods of time.

    Cause

    • As mentioned, converter shudder is usually temperature related. As transmission fluid recycles back through the engine turbine, it picks up frictional heat. Once the amount of heat generated by this friction surpasses the transmissions cooler's ability to shed it, the fluid thins and power transfer becomes inconsistent. Other sources of heat build-up are are failing transmission clutches or bands, and blocked coolant lines or radiator. Overloading the transmission also produces excess heat, as anyone who has towed a heavy trailer up-hill can attest.

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    Diagnosis

    • Transmissions can shudder in a very similar manner to torque converters. To determine whether the shudder is tranny or TC related, run your vehicle for a little while till it begin to shudder and immediately park it. With your foot on the brake, put the transmission in Drive, and apply light throttle. If you feel shuddering, then it's the Torque converter; if not, then the problem is within the transmission.

    Solving the Problem

    • Unless there is physical damage to the converter or transmission, shudder is a fairly easy problem to solve. Once the transmission fluid has been overheated enough times, it becomes permanently de-polymerized and need to be replaced. You can do this yourself by draining the transmission and flushing it, or taking it to any competent mechanic for maintenance.

    The Band-Aid Fix

    • All auto-parts retailers sell some sort of transmission additive designed to thicken the fluid. Lucas brand is the most popular and is recommended by specialists like Mr. Transmission, but is usually the most expensive. Those with older (pre-2000) GM and Chrysler transmissions can try adding a quart of Ford Type F transmission fluid, since it contains friction modifiers that the stock Dextron does not.

 
  #14  
Old 10-01-2012, 04:35 PM
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Probably not worth worrying about.
If my transmission dies, it dies.
I have already spent way too much time on it.

The fact there is not a dip stick was a bad decision.
Way too hard to service this transmission.
 
  #15  
Old 10-01-2012, 04:50 PM
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Originally Posted by jfall
Probably not worth worrying about.
If my transmission dies, it dies.
I have already spent way too much time on it.

The fact there is not a dip stick was a bad decision.
Way too hard to service this transmission.
Agreed i drove an 89 Olds with a shudder no one could fix for 100k ......I'll not lose any sleep,i only did one change and i need to drop again soon, I'll be extra sure on what i do then....
 
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