350B Torsional Isolator

rdrexler · Post by **rdrexler** » Tue Sep 16, 2014 6:20 pm

Hi all:

I bought a 350B that is in pretty good shape for a few thousand at an auction.

The steering cluthes were locked up and I replaced the steering clutches and brakes. Everything was going great pushing a bit of dirt when the dozer developed a pretty sever vibration that could be felt in the floor plates. When moving the dozer to look into the issue it stopped moving with a grinding sound.

The dozer has a reverser so I pulled the engine to see if the issue was with the isolator or the reverser. The isolator assembly was very loose on the flywheel - meaning I could grab on to it and move it around - including being able to pull it away from the flywheel about 3/4 of an inch.

Taking the isolator off of the flywheel it is apparent that the isolator is shot - the splines on the isolator are extremely worn with fresh tell marks where I think the isolator was slipping on the reverser shaft. Since the isolator assembly was loose on the flywheel I am wondering if the springs, flywheel anchors and isolator anchors should be replaced. The technical service manual does not seem to have any information on how to assess whether these parts should be replaced.

The input shaft on the reverser does not appear to have any damage but I don't know how to tell if the shaft is worn to the point that it could have contributed to the isolator failing.

I think the reverser is okay - but I have some reservations about replacing the isolator, putting it back together and then finding there is still a problem.

Any advice would be greatly appreciated. I am new to dozers and want to fix this right.

Thanks in advance.

Regards,
Ron

cantbeatadeere · Post by **cantbeatadeere** » Tue Sep 16, 2014 6:48 pm

New to dozers aswell Ron, picked up a 350c last weekend that has a loose sounding knock even with the clutch in, very loud at low rpm, I am getting everything in the shop set to pull the engine this weekend to replace the isolator which I am certain is the noise. The isolator has been revised 3 times and the current # is -at315819- and sells for 1123.51. I am praying I don't find any other problems while doing this repair...did you remove the blade to pull your engine??

Jamie

rdrexler · Post by **rdrexler** » Tue Sep 16, 2014 6:57 pm

Hi Jamie:

I left the blade attached. Took 4 hours to pull the engine. I do not have a gantry crane, so I used an engine puller - it worked but was a bit awkward.

Will the part numbers you gave work on my 350B? I am in the process of looking up the parts on jdparts.com. Doing a quick search it does not appear these parts on available after market so I am expecting the parts to be a bit expensive.

Ron

rdrexler · Post by **rdrexler** » Tue Sep 16, 2014 7:00 pm

I forgot to mention, to use the engine puller we first had to raise the dozer on the tracks about 6 inches so the engine puller could reach the engine. We used the blade to do the lifting - so getting this setup before beginning the disassembly was important.

Ron

cantbeatadeere · Post by **cantbeatadeere** » Tue Sep 16, 2014 7:21 pm

Aaaah, good idea, with the planks, you put them left to right instead of front to back, I have some 8x8's to put under it, do you have to remove the under pan?..pics of the project?...the parts are not available aftermarket and to be honest I'm not sure if they are the same. I also only have an automotive type eng. hoist.

rdrexler · Post by **rdrexler** » Tue Sep 16, 2014 7:52 pm

Yes - put the planks side to side. I also blocked up the blade so the hoist legs could slide under the blade when pulling the engine away from the reverser housing.

Had to remove the pan - 15 bolts all together (4 in the front, 3 on each side of the front, 4 near the back and 2 on each side for the straps- they all came out easy with impact. The radiator came out with the engine - kind of nice so did not have to drain the coolant. Once you disconnect all of the linkage, battery cable, etc from the engine there are only 4 bolts holding the engine to the reverser housing. It was kind of surprising to see so few bolts holding it together.

I took some pics with my phone - but looking at them they are blurry. I have a few decent pics but I am not sure how to attach pics to this forum.

Ron
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rdrexler · Post by **rdrexler** » Tue Sep 16, 2014 8:08 pm

I figured out how to share the pics. I hope this works:

https://plus.google.com/photos/11240259 ... 4677023345

rdrexler · Post by **rdrexler** » Tue Sep 16, 2014 8:16 pm

Finished researching parts. If I get the isolator, springs, isolator anchors and flywheel anchors it is going to be about $1550. I am going to wait to order any parts until I can get some input on how to determine if I need to replace anything more than just the isolator.

cantbeatadeere · Post by **cantbeatadeere** » Wed Sep 17, 2014 4:22 am

In the same boat trying to find out all I can, looks kike it may be wise to pull the reverser and check the splined shaft between that and the transmission and inspect it for wear, grease with high impact moly grease if its good. Other reading on here sounds like the "kit" to fully upgrade the isolator is about 1700.00, I am going to look into this further as this claims to make it so you will never have to repair it again...that would be fine with me.

rdrexler · Post by **rdrexler** » Wed Sep 17, 2014 7:40 am

Reading other posts I found the part numbers to upgrade the isolator the the 350D style, but JD says the parts are no longer available. If you find a source for the isolator bits, the flywheel and such please let me know.

I will probably pull the reverser to check it out.

This dozer is for personal use so down time is not a huge issue - I just don't want to keep tearing it apart.

Post by **Lavoy** » Wed Sep 17, 2014 8:42 am

I have all the leg work done to get the rubber isolators made, never was able to get anywhere on getting flywheels made. Used ones are probably around, so that may not be as big of an issue.
I kind of abandoned the project due to quantities necessary on the isolator, wasn't sure how many would actually sell.
Lavoy

Tigerhaze · Post by **Tigerhaze** » Wed Sep 17, 2014 11:44 am

I want to say that this is a thread on this board about the torsional isolators that also discusses the acceptable condition of the input shaft but am not able to find it at present.

EDIT: This was one of the threads that discussed it; unfortuntately it is sort of hard to understand because one of our former members deleted all of his posts but may help you some. See Jdemaris's advice about the dial indicator about halfway down.

http://www.jdcrawlers.com/messageboard/ ... =torsional

This was also a great thread on torsional isolators:

http://www.jdcrawlers.com/messageboard/ ... =torsional

rdrexler · Post by **rdrexler** » Wed Sep 17, 2014 6:10 pm

Thanks for the link to the thread on the input shaft. I will definitely do this check.

Without the availability of the upgrade components (isolator and flywheel) it looks like my options are to either buy the new parts for my setup or remove the reverser and install a mechanical clutch. I think I might research the conversion to the mechanical clutch checking on the durability and reliability along with the expense.

I am planning a trip to a salvage yard this weekend to see if I can find the bulk of what I would need to do a conversion. I know I will need the clutch housing, clutch pedal assembly, flywheel, drive shaft, coupler, clutch, pressure plate and throw out bearing. Doesn't look like a daunting task to convert but could be expensive. I could also be underestimating the amount of work.

cantbeatadeere · Post by **cantbeatadeere** » Wed Sep 17, 2014 6:41 pm

All the talk on here .... started tearing into mine tonight to see how much its going to cost me to get this thing right!!, just the muffler was 400.00, few other thing and it was a grand before I could blink. now the isolator and components......OUCH. hope when its done I can turn my back on it for a while.

cantbeatadeere · Post by **cantbeatadeere** » Fri Sep 19, 2014 5:02 am

Well, I got it out...isolator wobbles all over hell, its like all that is wrong is the springs are stretched a bit, still material on the isolator and it has a stamp of 4-2-02 - is that a date stamp??, what holds the isolator tight to the flywheel? off to deere today - ooh..the reverser coolant lines had a oil dripping out and it was a slight milky color, didn't look to bad when checking the fluid. MORE $$$$$$$$

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