Old JD165 trans slips when hot

[viabill]

I'm new to this forum, but I've been a JD owner for many years on a residential level. Now, I have a problem with my 1986 165 lawn tractor I hope someone can help me with.
The hydro transmission gets weaker as it gets hot. I can't mow 1/4 acre withoout having to shut it off and let it cool down. After about 10 minutes of mowing, you have to move the lever forward more and more to keep up pace, and after a few more minutes it won't move at all unless you get off and walk beside it (with the blade disengaged, of course).
Is the transmission bad, or is there some fix for it? I have heard that there is a kit that can be installed on the trans oil filler tube to keep it from absorbing moisture from the air. Would this help? Is it still available?

 

[jerrybob]

Sorry to hear about your problem. I recently had the same problem with my LT180 tranny.....when warm.....just couldn't get up any incline. I have lots of hills.....run chains most of the year. I take really good care of the machine but just wore the tranny out. Unfortunately......had to put new tranny in for about $850. Runs like new now.....hope to get another 7 years out of this tranny. There is a guy out there who will rebuilt a hydro trans but said his starting price is about $900. I was able to get a new trans and have JD dealership install for price above. That included a new drive belt as well. Good luck!

 

[KENSFM]

You may need to have your transmission rebuilt, but before you spend the money try changing the fluid (make sure to use the correct fluid) and filter. This will not cost too much and may solve your problem.
Good luck, Ken

 

[viabill]

Thanks for the inputs, guys. I'm going to try KENSFM's suggestion of changing fluid first. If that doesn't work, JD sells this trans for $530 and I'll have to decide if it's worth the investment to replace the trans.

 

[BobOB]

I checked my 165 technical manual, and this is the fluid it takes: SUNDSTRAND HYDROSTATIC
TRANSMISSION OIL?85 (S.N. 475001 )
SAE 10W 30 engine oil with an API classification of SE,
CC or CD is recommended in the transmission.

The 165 is a great little tractor. I just replace the motor in mine and it still runs great. There are a lot of parts still available. Let us know if you solved the problem.

 

[viabill]

Well... so far I have torn the 165 down to the frame rails and engine, but haven't gotten anything put back together, yet. I am planning to go change the xmission fluid using teh 10w30, as BoBoB suggested, and I also got a filler tube kit that includesa bladder that is supposed to keep the fluid from absorbing moisture from the air and contributing to the loss of pulling power.

I am also rebuilding the 38" deck, since most of trhe bearings are bad. I'm also trying to figure out how to correct a tilt in one of the blades. Apparently, we hit somehting while mowing that bent the deck around where the bearings for one of the blades mounts, causing a tilt in only that blade.

So, it will be some time befoer I ghet things put back together to find out how successful the fluid change was, but I'll let you all know when I find out. Let's just hope that the fluid corrects the problem, otherwise I might be out a lot of $$ for the ther repairs I'm making.