transmission down shifting or jerking

[cmartin248]

Many times the transmission is repaired or replaced when the fix can be very simple. For the past few months my 4.4L X5 has been having a transmission problem. While driving it would suddenly down shift 1 to 2 gears and rev the engine to the point of backing off the accelerator. After searching the boards and using some logic, it did not appear to be a mechanical problem. The problem was electrical because it did not slip or act like a mechanical failure. I found a couple of articles where drivers had replaced the internal transmission wiring harness due to a short to the temperature sensor. The harness cost $250 and is way over priced. My thoughts were to find the short and repair the harness. After removing the pan, I found two temperature sensors. Both had a double push on spade connection. I took the sensor and stuck it into the spade connection, one side at a time. I found one of the connections was very loose, so I sprung the spade connection back tight and everything has been fine for several hundred miles, more than enough for the problem to occur again. Total cost was $25 for the fluid and about 2 hours work. Too many people have a transmission problem and simply drive it to the shop at the mercy of the mechanic. You guys act like the transmission is a magical box that only the magicians can fix.... I diagnose the problem (with some help from other on this board) make the repair and fixed what's wrong. Wish all mechanics did that, but then it's not financial advantagious for them.

[ognjen]

Originally Posted by cmartin248

Many times the transmission is repaired or replaced when the fix can be very simple. For the past few months my 4.4L X5 has been having a transmission problem. While driving it would suddenly down shift 1 to 2 gears and rev the engine to the point of backing off the accelerator. After searching the boards and using some logic, it did not appear to be a mechanical problem. The problem was electrical because it did not slip or act like a mechanical failure. I found a couple of articles where drivers had replaced the internal transmission wiring harness due to a short to the temperature sensor. The harness cost $250 and is way over priced. My thoughts were to find the short and repair the harness. After removing the pan, I found two temperature sensors. Both had a double push on spade connection. I took the sensor and stuck it into the spade connection, one side at a time. I found one of the connections was very loose, so I sprung the spade connection back tight and everything has been fine for several hundred miles, more than enough for the problem to occur again. Total cost was $25 for the fluid and about 2 hours work. Too many people have a transmission problem and simply drive it to the shop at the mercy of the mechanic. You guys act like the transmission is a magical box that only the magicians can fix.... I diagnose the problem (with some help from other on this board) make the repair and fixed what's wrong. Wish all mechanics did that, but then it's not financial advantagious for them.

My 2000 4.4 x5, jerks when i go left and around 40km-50km an hour. And it will jerk more and more until i let go of gas. I dont think that will fix the problem on my car? And I dont think its transmission? What do you think?

[X5 Meister]

Photos with your write-up would go a long way to helping out lots of people with similar issues. Can you do a full write-up?

Originally Posted by cmartin248

Many times the transmission is repaired or replaced when the fix can be very simple. For the past few months my 4.4L X5 has been having a transmission problem. While driving it would suddenly down shift 1 to 2 gears and rev the engine to the point of backing off the accelerator. After searching the boards and using some logic, it did not appear to be a mechanical problem. The problem was electrical because it did not slip or act like a mechanical failure. I found a couple of articles where drivers had replaced the internal transmission wiring harness due to a short to the temperature sensor. The harness cost $250 and is way over priced. My thoughts were to find the short and repair the harness. After removing the pan, I found two temperature sensors. Both had a double push on spade connection. I took the sensor and stuck it into the spade connection, one side at a time. I found one of the connections was very loose, so I sprung the spade connection back tight and everything has been fine for several hundred miles, more than enough for the problem to occur again. Total cost was $25 for the fluid and about 2 hours work. Too many people have a transmission problem and simply drive it to the shop at the mercy of the mechanic. You guys act like the transmission is a magical box that only the magicians can fix.... I diagnose the problem (with some help from other on this board) make the repair and fixed what's wrong. Wish all mechanics did that, but then it's not financial advantagious for them.

[cmartin248]

I want everyone to know that my initial repair was a temporary fix and did not fix the problem. What I thought was temperature sensors, were actually pulse generators (impedance coils). I guess while was checking the wiring, I did enough movement of the wires to make the temperature sensor that is built into the wiring harness to makeup and work correctly for a while. The weird shifting pattern of high rpms followed by hard down shifting was cause by the transmission wiring harness internal temperature sensor. This sensor is a small looking resistor about 1/8 inch long and 1/16 inch in diameter that is crimped between two wire. When heated with a heat gun, the resistance increased. I bought the harness for $190 and had a local trans shop install it for $150. My X5 no longer has a transmission with its own mind. Hope this helps others...

[lamv225]

What is the part number for the harness? Can you go into further details as to where this harness is located?

[KDAWG97M3]

Anybody have this part number? My buddy put the gt1 on the x5 and showed this tranny temp sensor 34. My car has zero issues but I want to fix before it does become a issue..

My only fear is my car has 130k miles and not sure if the fluid has been changed in the tranny...is this bad? Can I change the fluid or should I just leave it....I am getting mixed responses on changing/not changing the fluid?

[Big "J"]

Don't fix it if it ain't broke! They (tranny's) will go eventually whether it be during your possession or the next person.

Take care of it and it will last for as long as you want.

[KDAWG97M3]

Originally Posted by Big "J"

Don't fix it if it ain't broke! They (tranny's) will go eventually whether it be during your possession or the next person.

Take care of it and it will last for as long as you want.

What? Don't fix it, but take care of it....so what are you suggesting?

[Big "J"]

Sorry... Didn't mean to confuse.

I was suggesting that if it's driving with no apparent issues as you mention, there's no need to replace the fluids and filter until it starts to have problems.

Do regular maintenance of oil, filter, p/s fluid, brakes, etc... It will last as long as you want.

[RRPhil]

The 5HP24 wiring harness part number is 24 34 1 423 719





and this is the positive temperature coefficient sensor :



Phil