nhrc1 1 #1 Posted May 28, 2011 I have a 1976 D-160 with an F E L. I was moving gravel for about 3 hours no problem, then I went to back-up and went about 5 feet and it stopped with a screeching sound as if you were pushing against a wall while pushing the D C L . Put it in forward 5 feet same results. The rear and deck hydraulics work the hydro motor is spinning; I did see some oil under hydro motor on cross member. I turned the screw on the side to disengage the hydro to roll it in to the garage when I try to roll it same thing 5 feet either direction, It just locks up. I know this isn Share this post Link to post Share on other sites
gzx3sc 0 #2 Posted May 28, 2011 I've heard of this issue. There are several bolts in the transaxle that hold the differential parts together. Either a nut comes off one of the bolts or the head of the bolt shears off. There's not enough room between the casting and ring gear for the nut so it locks up. If you force it, you'll bust the casting. I'm going off of what I've heard. I've not experienced this myself, but I have two rebuild transaxles just in case. Share this post Link to post Share on other sites
nhrc1 1 #3 Posted May 28, 2011 Thats what i thought it could be. I also read something about the parking paw, but I can't find the thread that mentioned it. Share this post Link to post Share on other sites
tunahead72 2,439 #4 Posted May 29, 2011 Did you try a search on "parking pawl" (not "paw")? :hide: Share this post Link to post Share on other sites
gzx3sc 0 #5 Posted May 29, 2011 You might get a chipped tooth off the parking paw but unless it wedges between the ring gear teeth I doubt if it would cause a problem. That would explain the 5 feet forward, 5 feet back (one revolution of the ring gear before hitting the pinion gear. Share this post Link to post Share on other sites
squonk 41,397 #6 Posted May 29, 2011 I have almost the same problem with my C-160. Was the differential problem with the D's only or is it a problems on other's too? Share this post Link to post Share on other sites
refracman 167 #7 Posted May 30, 2011 The Ds were the only ones that had this as a regular problem, undersized bolts that hold the diff together. The fix is to to upgrade the size of bolts. Just another problem that the Ds have. Its a shame they quit makeing them, by the end of production they had most of the problems fixed. Share this post Link to post Share on other sites
nhrc1 1 #8 Posted May 30, 2011 When you say undersized bolts that hold the diff together do you mean the cases or is it internal bolts? What would the steps be to remove the transaxle, and is there a manual I could down load. Thanks for your input. Share this post Link to post Share on other sites
pfrederi 17,893 #9 Posted May 30, 2011 I think the correct term would be under strength bolts in the differential. When I fixed my D200 I used some Grade 9 special bolts from McMaster. You will have to split the transmission and removing the hubs can be a real PIA...start soaking them now. (Click for full size) Also do not try to force moving it or you may break the trans case. You need to download the Sundstrand hydro manual available from Toro and other places Share this post Link to post Share on other sites
nhrc1 1 #10 Posted May 30, 2011 Thanks for the reply, I like to try and confirm what I think I should do with some one that has done it so I don't brake something and hen say I thought that Share this post Link to post Share on other sites
pfrederi 17,893 #11 Posted May 30, 2011 Dave when you remove the manifold the only thing that may fall out are the O rings. They are sort of unique (the round ones were not in my set of 1000 o rings and the two square ones used as backers on the high pressure ports are really unique). They are all available from Toro, and you should probably plan on replacing them. I found the round ones from Mcmaster but as you had to by 100 of two different sizes Toro was cheaper. There also is a special sealing washer on one bolt which is NLA from Toror. You might get away with reusing ..I used a copper crush washer which seem to work OK. I would get a case gasket and also as long as you are this far in I would remove the hydro motor from the transaxle and check the screen filter behind it. It has a magnet to attract chips etc. Therefor I would also get the gasket that goes between the motor and the transaxle. (I am not a big fan of using silicone...It can get into places it doesn't belong). Incidentally I bent that puller working on the other side...those hubs are a real PIA and you can break them easier than pulling them... Share this post Link to post Share on other sites
pfrederi 17,893 #12 Posted May 30, 2011 Dave: These are the High strength bolts from McMaster I used in my D200 90201A333 1 Pack Grade 9 Alloy Steel Hex Head Cap Screw, Zinc Yellow-plated, 3/8"-16 Thread, 3-1/2" Length 93591A300 1 Pack Grade 9 Oval-top Hex Locknut, 3/8"-16 Thread Size, 9/16" Width, 25/64" Height 1 Share this post Link to post Share on other sites
nhrc1 1 #13 Posted May 31, 2011 Thanks for the info. I got it up on jack stands and took the wheels and lower lift arms off the 3 point tonight. Also got one hub off (that leaky oil seal helped!) I Share this post Link to post Share on other sites
pfrederi 17,893 #14 Posted June 1, 2011 The axle keys are woodruff keys (half round). Usually I drive down on the inner end with a brass drift pin. Share this post Link to post Share on other sites
nhrc1 1 #15 Posted June 8, 2011 Finally droped the transaxle today. Got it up on the bench and when I rock it I hear something rattling inside, hopefully that is the broken bolt in the differential that gzx3sc mentioned. Now for my next questions (1) pfrederi mentioned square o-rings all I saw under the manifold on the transaxle were round ones. I only saw 5 o rings on transaxle (none stuck on manifold) Is there a ring under a ring, is that what the parts manual calls Share this post Link to post Share on other sites
Trouty56 567 #16 Posted June 8, 2011 There also is a special sealing washer on one bolt which is NLA from Toro. You might get away with reusing ..I used a copper crush washer which seem to work OK. Paul mentioned the NLA washer above in a post. Maybe you missed it. Share this post Link to post Share on other sites
pfrederi 17,893 #17 Posted June 8, 2011 The 2 high pressure ports each have 2 O rings. One is regular profile (round) the other is a backer ring and has a square profile. Sorry I didn't describe that really well before. As I said the only viable source I found was Toro. Share this post Link to post Share on other sites
nhrc1 1 #18 Posted June 9, 2011 Thanks for the info. I didn Share this post Link to post Share on other sites
pfrederi 17,893 #19 Posted June 9, 2011 The needles should not be put back. When I had mine apart I replaced most all the bearings except one 8049 (replaced by 5960) is NLA. It is on the motor end of the gear shaft. I went to Bearings and drives unlimited and Motion industries and couldn't find a replacement so it went back in as it was. Share this post Link to post Share on other sites
nhrc1 1 #20 Posted June 10, 2011 Thanks for all your info on the o-rings Paul, after looking at the parts view for the 100th time I realized that there are 3 different o-rings. On the transaxle end it shows all the o-ring but only 2 reference numbers on the hydro motor side it shows all the o-rings and 3 reference numbers! I didn Share this post Link to post Share on other sites
Conrad 0 #21 Posted August 12, 2013 Hi, I just found this thread. I have the same problem with my D-160. The rear axle will turn 1/2 revoution either direction and lock up. I'm courious as to how you did with your repair. I'm trying to decide what to do with my tractor. Ant info you can give me would be great. Thanks, Conrad Share this post Link to post Share on other sites
brandonozz 168 #22 Posted August 13, 2013 Take a look at this picture and note the bolt that is on the right. There are 4 bolts that hold the bull gear and pinions in place and the bolt on the right had broken or nut came off. When that happens the bolt will slide out and as the gears turn it will hit the gear that is in the middle. Normally the bolt heads run between the two gears. Not a problem to fix and if you dont actually break the bolt and get loose bolts/nuts rolling around while still running the tractor you can keep from breaking your case. The bull gear/ring gear runs close to the case so any loose metal can get caught between and crack the case - like happened to mine. Its all good now with grade 9 bolts and a new case. Not a hard repair but time consuming. We will help you all we can. 1 Share this post Link to post Share on other sites
Conrad 0 #23 Posted August 14, 2013 Brandon, thanks for the info and the picture. Looks like I'm in for a challenge fixing this. I do believe my case is not cracked so that's a good start. Conrad Share this post Link to post Share on other sites
pawillie1947 0 #24 Posted November 24, 2013 Hey Guys the PO of my D180 ignored the problem (was still moving ) check out my pics and see what damage can be done. Share this post Link to post Share on other sites
jgauvin812 0 #25 Posted December 17, 2013 Just got done upgrading the differential I got for my D-200 from a D-160. Sharpened a masonry bit so it wouldn't drag on the sides of the carbide tip and opened the 5/16" holes in the ring gear to 3/8", did this on a Bridgeport for rigidity so the drill wouldn't chip. Re-sharpened the drill point each hole and I made it through all four holes, cut at 130 RPM dry. Opened the holes on the side castings with a standard high speed steel twist drill. Installed new L9 bolts and locking nuts. Some new axle bearings and seals and we should be all set. Share this post Link to post Share on other sites
