Ref: My signature truck (86/92 Retro).
At the time we did the retrofit, I purchased a used automatic trans. We did a serial number check with a Dodge dealer and was told it was a "518". It is an overdrive transmission. It has performed flawlessly up until a few days ago. Still performs like it should, it just seems to be noisey (all of a sudden). Sounds a lot like an old standard trans car or truck winding up or down through the gears. My overdrive is on a driver operated only switch. Going up through the gears (accelerating normally). It "whines" through all the gears (not unbearable, but noisey). Loudest at about 61 mph. When I let off the throttle in OD, of course, it goes quiet as it is basically free-wheeling. When (at about 40 mph) I switch out of OD the noise comes back and continues until I stop.
When we installed it, we added a deep sump pan and pickup and a temp gauge at the rear of the pan. Trans has never gotten over 187 degrees. That was while pulling 7100 lb trailer from Phoenix to South Fork, Co. last summer. Normally will not move the gauge off the 140 degree bottom line.
About the same time the noise started, it ran in the 150 to 160 degree range for about three days (normal local driving - 90 to 98 degree ambient air temp). It has two coolers. Block mounted tank type and small air type mounted front left in front of raditor. It has 1/2 inch copper lines to and from the front cooler. The check valve (in line) to the block mounted cooler has been removed as recommended by several people. Truck is never driven without allowing the trans to pump itself up (due to no check valve).
I pulled the pan and the pan was totally clean. No band/clutch material and no metal particles. Has been on Amsoil fluid since installed. Fluid looks and smells new.
To rule out rear axle noise, I removed cover and checked it also. Same story as the trans. Clear gear oil (Amsoil 75/140) and no metal (magnet looked like someone had lightly smeared "never sieze" on it. Only particles found. No slop in gears.
So, now the questions! Do any of you have any ideas as to what might be the source of the noise? In the worst case senario, if I need to replace the trans, any suggestions as to what and who to get one from?
Thanks
Jim
At the time we did the retrofit, I purchased a used automatic trans. We did a serial number check with a Dodge dealer and was told it was a "518". It is an overdrive transmission. It has performed flawlessly up until a few days ago. Still performs like it should, it just seems to be noisey (all of a sudden). Sounds a lot like an old standard trans car or truck winding up or down through the gears. My overdrive is on a driver operated only switch. Going up through the gears (accelerating normally). It "whines" through all the gears (not unbearable, but noisey). Loudest at about 61 mph. When I let off the throttle in OD, of course, it goes quiet as it is basically free-wheeling. When (at about 40 mph) I switch out of OD the noise comes back and continues until I stop.
When we installed it, we added a deep sump pan and pickup and a temp gauge at the rear of the pan. Trans has never gotten over 187 degrees. That was while pulling 7100 lb trailer from Phoenix to South Fork, Co. last summer. Normally will not move the gauge off the 140 degree bottom line.
About the same time the noise started, it ran in the 150 to 160 degree range for about three days (normal local driving - 90 to 98 degree ambient air temp). It has two coolers. Block mounted tank type and small air type mounted front left in front of raditor. It has 1/2 inch copper lines to and from the front cooler. The check valve (in line) to the block mounted cooler has been removed as recommended by several people. Truck is never driven without allowing the trans to pump itself up (due to no check valve).
I pulled the pan and the pan was totally clean. No band/clutch material and no metal particles. Has been on Amsoil fluid since installed. Fluid looks and smells new.
To rule out rear axle noise, I removed cover and checked it also. Same story as the trans. Clear gear oil (Amsoil 75/140) and no metal (magnet looked like someone had lightly smeared "never sieze" on it. Only particles found. No slop in gears.
So, now the questions! Do any of you have any ideas as to what might be the source of the noise? In the worst case senario, if I need to replace the trans, any suggestions as to what and who to get one from?
Thanks
Jim