Finally got around to picking up the aftermarket track recoil spring on the RH track on my 941 Loader, Ser # 80H 2988, getting it up from our local Cat dealer. After matching it up to the old spring which has a caged length of approx 23" when on the machine, as compared to 29" of free length for the new one they shipped. New one seems too long. Can anyone who has changed these out give me an idea of what the difference in length should be, unrestrained vs when it is installed? I am thinking that it should only compress just an inch or 2 when installed from it's free un-caged length & that perhaps they sent the wrong spring. I checked with the dealer & am waiting for them to get back to me.........
Yair . . . Metalman 55 If the springs only had to compressed an inch or two it wouldn't be an issue . . . I think six inches sounds about right and is why these things are deadly dangerous if not securely caged during compression and installation of the centre bolt. . . there are threads on this subject, Measure the gap between the coils of a good installed spring versus your new spring and calculate the difference would be a way of confirmation. Cheers.
Here's the specs. If you are unfamilliar with this kind of work, beware. 7K639 Recoil Spring: Assembled length for installation ... 20.89 in.(530.6 mm) Free length ... 28.62 to 29.38 in.(726.9 to 746.2 mm) Force after installation ... 7.4 to 8.6 ton(6.7 to 7.8 M.ton)
A job not for the uninitiated IMHO. There was a thread on here somewhere about a guy who built his own press to install recoil springs - here - HeavyEquipmentForums
Looks like the correct spring. I was not aware that the spring must compress that much. We will proceed with caution.........
Thanks for that helpfull information.
We have a large hyd press in our shop & I made up this sketch of an assembly to contain the spring while pressing it down. The upper sleeves is a piece of 8" SCH 40 pipe (2'-2" lg.) which is welded to a piece of 3/4" plate at its base 14" od x 4" id, then a short piece of 10" SCH 40 pipe x 5" long at the bottom with a mouse hole in the one side to reach in & put the nut on once the spring is compressed. Sketch shows the spring relaxed @ a length of approx 29" & compressed at 20 7/8", when assembled. Has anyone used an idea like this?
This type of spring usually has "caps" on each end. One is a plate with a hole in the center, the other end has the guide for the track adjuster cylinder. A long threaded bolt with a square head runs down the center of the spring. The bolt is dropped into the guide end which has a square pocket that matches the bolt head. The spring is compressed until the bolt comes out the other end and then the nut is screwed on. In this case it needs to be compressed about 8-9 inches. When compressed to this dimension it has about 10 ton on it. You take the spring assembly and drop it into you roller frame. Once you have it in you roller frame in the correct location you back the nut off until the spring is being held in place by the frame. On the above "assembled length for installation" means you need it compressed to at least this dimension for you to get it into the roller frame. Your best option is to have it pressed at the Cat dealer or an independent repair shop. You will need a few more parts also. You will need to get your old spring out. Looks like it's broken at the second coil from the left. This can be dangerous also. Make sure the long bolt I mentioned above is still in one piece. If it is you might be able to tighten the nut to compress the spring enough to remove it. If the bolt is broken or you can't compress the spring you will have cut the spring into pieces to get it out. This is wild and exciting to do. Warning: Never remove the nut once the spring is assembled and not installed. Once installed don't take it off either. FYI the spring in the picture is actually an aftermarket part. If you got it from you Cat dealer he probably sold it as a Cat Classic part. Nothing wrong with the Classic parts. Hope this info helps. James
Well, we finally got at cutting out the old recoil spring & then cleaned up all the parts that we plan to re-use in the blaster. Some work in progress pictures of cutting the old spring out (no surprises there fortunately), some of the build up on the worn parts & then touch up paint on the parts once cleaned up.
Here is a couple of pics of us pressing down the new recoil spring, with the related components in the shop press, using our homemade pipe sleeve assembly. Note on the 2nd picture, at the bottom right where we left a mouse hole to reach in & thread the nut on the end of the long bolt. We were a little nervous when compressing the spring, having never done that job before, but it went ok.
Here are the hyd adjuster components all cleaned up & ready for the seals to go on & be reassembled.
A little bit of fear when doing a job like that, whether for the first time or the 100th, is no bad thing IMHO. It makes you careful about how you do the job.
Got the spring installed again, along with the hyd adjuster. One problem.......as seen in on of the previous photos of the hyd adjuster components, we cleaned everything up well as shown in the photos & reinstalled the seals & once everything is back together we cannot get the adjuster to extend when we pump grease into it. Note the adjuster is pretty well fully retracted now, as we had taken a link out of the chains recently as it was nearing the end of it's adjustment. Any ideas why the adjuster will not move? It is not a problem right now as the track is just right where it is, but when it wears it will be.
Do you mean you're pumping grease in and nothing is happening, or you can't get grease in as if something is blocked?
It is blocked & when pumping under a great deal of pressure nothing moves. It does not leak out anywhere. We were quite surprised as everything cleaned up so well & looked great as far as the adjuster is concerned.
Is the grease fitting clear? Try removing it and see if you can get grease through.
We did that & even tried switching to the other location where the vent is...........
I hate to ask, did you reassemble as found and disassembled or as the service manual shows? If you put the piston in backward the chance of a piston seal can block the grease hole can happen.
Will the idler actually move. It may be seized in the guides.
We actually have a spare hyd adjuster assembly in the shop & we examined it carefully after this problem surfaced. We are quite certian we put it in correctly....the 2 wider fiber guides go in first & the seal & thin retainer ring is on the end that faces the idler. Will try to do some more investigating in the morning. The idler moves freely as well.
It sounds like you've got the piston in the right way. As you know, it's a dead simple system and there's nothing much to go wrong. My money is still on the grease valve. Try swapping it with the one on the left.
Found the problem.........an easy one. I had no rubber gasket under the fill valve.....guess it needs that to keep up a bit to unseat & allow grease in. Found another plug with one on, put it on & it works fine.
It had to be something simple ....... Now you need to tidy up the tool you made for installing the spring, paint it, and offer it for rent to others who are looking to do the same job.
Now there is a good idea!!
Any idea why we need the rubber gasket installed under the top flange of the fill valve to allow grease to flow in to extend the track? As soon at I put the gasket in, the adjuster moved as smooth as butter & absolutely no movement before.
Purely a guess , it was bottomed out? These things happen to me all the time. There are things that happen to me no body has ever seen or heard of. I should write a book.
Took the cover off of the other side of the machine & see it has a broken spring as well & someone botched things up by putting a think homemade shim plate in the back, likely to compensate for the broken spring length I am thinking. Anyhow, ordered a new spring & rear seat plate. Not sure if the old seat plate is in there or what it's condition is. Have a spare long bolt & rebuild kit here for the adjuster here already. Plan to take a link out of the track chain as we did on the other side, while we are at it, as it is almost at the end of it's adjustment.
Here we go on the left side of the 941 Loader......forgot to take pictures when I was cutting the old spring out. Cutting it out was uneventful. Had to do some doctoring up on the wings of the front pilot where it fits into the 2 retainer shoes. Both front dowels on the retainer shoes were broken off, so we drove the old ones out & will install new ones. Sandblasted & painted all the loose parts that get reused. Plan to compress the spring tomorrow & re assemble. The seals in the hyd adjuster were in need of replacing, so have new ones to install.
Here we are pressing the track recoil spring down in the home made compressing device that we made for the other side, then some pictures of the install. A bit of a scary job, as you think about what would happen if something let go!! We took a link out of the track on this side as well, while we were at it, as it was about at the end of the adjustment. Rebuilt the hyd tensioner while it was apart as well. Can anyone tell my what the 12" +- long pipe sleeve that slides over the long bolt does? We put a new center long bolt in, but reused the sleeve as it was still good.
Here it is all cleaned up & painted!!
What is the part number for the square headed bolt for the adjuster? The threads on mine are gone. Any other part numbers for the adjuster would be great also.
Parts manual from cat dealer says 7k-0694. Will a 9k-5446 or 9k-5354 work?
What all other parts are you looking for? I will try to get back to you on the long pilot bolt when I can.
Still trying to get the one adjuster apart. It is very rusted. So the pilot and the barrel? not sure.
I am away from the office for a few days but had someone else look up the number of the long bolt for me. They said it is 7K0727, if your machine is the same as my 941. My ser # is 80H2988. If you refer back to my earlier posts in this thread, you will see my various track adjuster components apart & cleaned up, which may help you identify them & what you need. Perhaps if Old Magnet checks in, he could verify the part # of the long bolt??
7K0727 is correct for s/n 80H0568-up
Thanks for the clarification on that OM.
Finally got around to reinstalling the track recoil spring guards today after changing out the springs & rebuilding the hyd adjusters a few weeks ago. They were all beat up with some of the ears torn right off. Made up some new ears & welded them on & straightened the guards some. The front guards that cover the adjusters were missing & may just leave it that way. I wonder how much aftermarket guards for the front portion behind the idlers would run?
I thought I would pump some fresh oil into the bottom rollers & the front idlers while I have it up in the air. Much easier on the back & knees!