Wiggo
Member
Hello All,
I have a D7F serial number 92E1986 with the Cat 3306 engine and i am told that model has the lastest of the D7F transmissions, better than the earlier ones, but not as good as the D6C trans. A bit of History, purchased from a deceased estate as a very tidy machine, worked it on a few projects with this current transmission over heating problem. the motor got a knock in it so we pulled it out did a full out of chassis rebuild including the torque converter, the mechanic said he was 90% sure that the overheating was from a worn converter. so $50k later we still have a brand-new motor and a transmission problem.
Outline, the tractor will start working for the day build temp to normal working temps and stabilize, work it hard the water temp and the trans temp will rise and fall together, trans will change and work as it should, after about 3-4 hours the trans temp will start to climb ahead of the engine temp and from there on there is nothing you can do to correct it. You pull up and let the temps normalize the minute you work it the trans temp will climb faster than the engine temp again, we dont work it into red but once it gets hot the trans will stop pushing and the right-hand foot brake plays up. Its like a valve opens and is bypassing oil inside the transmission. shut it down and walk away. tomorrow morning it will start up and work like new again. it has a lot of blokes beat.
What we have done, checked and cleaned the suction filters, nothing worth reporting in them, pulled the cooler apart cleaned and checked, dropped the oil, replaced with a slightly heavier oil. checked the pressure on the Hyd pump and scavenger pump all tested ok (note i would like if someone had the pressures so i can double check) replaced the torque converter, none of this changed it in any way.
We have been doing light work with it over the past 12 months nothing has changed, now we have another dozer coming to chain some country, so really want to get it sorted so we can work a full day. any help would be greatly appreciated.
note the machine is out on one of our properties a few hours west so my response time to check things will be delayed.
I have a D7F serial number 92E1986 with the Cat 3306 engine and i am told that model has the lastest of the D7F transmissions, better than the earlier ones, but not as good as the D6C trans. A bit of History, purchased from a deceased estate as a very tidy machine, worked it on a few projects with this current transmission over heating problem. the motor got a knock in it so we pulled it out did a full out of chassis rebuild including the torque converter, the mechanic said he was 90% sure that the overheating was from a worn converter. so $50k later we still have a brand-new motor and a transmission problem.
Outline, the tractor will start working for the day build temp to normal working temps and stabilize, work it hard the water temp and the trans temp will rise and fall together, trans will change and work as it should, after about 3-4 hours the trans temp will start to climb ahead of the engine temp and from there on there is nothing you can do to correct it. You pull up and let the temps normalize the minute you work it the trans temp will climb faster than the engine temp again, we dont work it into red but once it gets hot the trans will stop pushing and the right-hand foot brake plays up. Its like a valve opens and is bypassing oil inside the transmission. shut it down and walk away. tomorrow morning it will start up and work like new again. it has a lot of blokes beat.
What we have done, checked and cleaned the suction filters, nothing worth reporting in them, pulled the cooler apart cleaned and checked, dropped the oil, replaced with a slightly heavier oil. checked the pressure on the Hyd pump and scavenger pump all tested ok (note i would like if someone had the pressures so i can double check) replaced the torque converter, none of this changed it in any way.
We have been doing light work with it over the past 12 months nothing has changed, now we have another dozer coming to chain some country, so really want to get it sorted so we can work a full day. any help would be greatly appreciated.
note the machine is out on one of our properties a few hours west so my response time to check things will be delayed.
