2001 cat 730 ADT

[chandler starling]

Good morning, This is my first post but I have been reading and following many different threads.

I have searched this site and the internet for info on separating a Cat 730, with no luck. S/n AGF 0366. I am new to the ADT world. I was able to pick this one up at a local auction for a fair price. As we were operating it you could see some movement in the bottom hitch pin. You can Occasionally Feel the slop in the cab. So I’m trying to gather as much info on the task of separating and replacing the pin, bearing and seals ourself, or should I take it to the dealer.

We have the equipment and tools to service our full fleet of equipment . This is just a new task. Also the operator complains about the ride being rough. Would this pin have something to do with that.

Any help or advice would be greatly appreciated.

 

[Nige]

Is your problem in the hitch itself or is it in the spherical bearing in the A-frame that mounts on the bottom of the lower hitch..? Section A-A in the illustration below, the spherical bearing #1 mounts in a tapered sleeve #5. TBH in our artics this is the most common area to get play rather than the hitch itself. Take a look to see whether or not the remote grease line for the spherical bearing is actually in one piece, they are usually bust which leads to bearing failure if not spotted. Cross your fingers that the worn bearing hasn't egged out the bore in the suspension frame #4.
Determining where the play is will be a key factor in figuring out what is the correct procedure to do the repair.

 

[CM1995]

On a side note I had an '01 725 and the wiring harness, I don't remember if it was the main one, going from the engine compartment through the cab was problematic. Owned the truck for 3 years and replaced it twice.

It's been so long I forgot what the actual failure was. Had a new '07 725 on lease for 2 years and never had an issue with the same harness.

BTW - Nige is the man to help you through this.

Welcome to the Forums!

 

[Cmark]

The bottom pin has a taper on both ends. The upper taper fits in the machine frame, the lower taper fits in the spherical bearing in the A frame. Try to work out if the movement is in the lower bearing/taper/A frame or in the upper portion.
If you have movement in the A frame part, no biggie.
If you have movement in the pin to frame interface, yes biggie.
Either way you should get it fixed sooner rather than later.

Rough ride. Check the nitrogen pressure in the front suspension cylinders.

 

[chandler starling]

Wow I don’t know why it took me so long to post. You all have posted and shared great knowledge in such a short amount of time. I really appreciate that.

Cm1995- about your wire harness. I am guessing that was common with these machines because my truck has a new wire harness on it and I believe a new ecm. I noticed how new the wires were when I first popped the hood. We just finished our job with it and we will be fixing it ASAP. Also how would I check the nitrogen levels in the front cylinders?

Nige/ Cmark- thank you for such great replies. The play that I can visibly see is between the pin and the A frame. Meaning, when we put it in gear and move forward a touch. The A frame will move forward till it touches the pin.

You mention about edging out the bore. I know if it did then I would have to get it lined bored. Is there a certain amount of movement when you know it will need to be line bored? When you put it in gear you have about 1/2 inch of movement .

 

[Cmark]

If you have 1/2" play in the A frame bearing you need to get it fixed. In time the banging will loosen the upper taper and then you have a whole new set of problems. If the A frame bore is damaged then it's easiest to take the A frame to a machine shop for boring and sleeving.
Each front suspension cylinder has its own separate accumulator. If you don't have nitrogen charging equipment you will need to find somebody who has to check the pressure. The ride height is then adjusted hydraulically using the two valves under the access covers.

 

[Nige]

Sounds like you need to drop the A-Frame ASAP and survey the damage. Be careful, it's a tad on the heavy side but comes out easily enough especially with a worn bearing.
An oval bore is a possibility, not guaranteed. The ones I've seen failed in the bearing itself and ended up replacing the bearing and the tapered sleeve as well as new hardware and other bits & bobs. Generally the seal #6 and the three bolts/washers #14, & #18. As I said before, check the grease line to that bearing, every one that I've seen within the past 2-3 years that failed the shperical bearing also had a busted grease line, and of course no-one ever gets down under the machine to check that the grease is going where it should be when they pump the grease into the fitting.

While you're into the A-Frame and front axle I would suggest you replace the rubber bushes in the transverse link #9 on the LH side of the illustration above. Don't do those bushes until you have the A-frame back in place though, the front axle could get a bit "sloppy"......

A comment about front suspension. It's also important to have the correct amount of oil in the unit, so if one or both of your units have signs of external oil leaks then they probably need to come off and be rebuilt, hopefully just with new seals.

 

[chandler starling]

Attached is the part diagram that I got from my dealer. I was thinking that I needed to replace the parts is part “B” of the diagram. But from what we talked about that would be wrong. I need the parts to rebuild the A frame. Am I following correctly ?

 

[Nige]

Everything revolves around the bottom of the pin marked B in your illustration above. That is where the tapered sleeve #5 in my illustration above mounts. IF the taper on the bottom of the pin is still good then you will not need to split the front and rear frames to get into the hitch bearings that are shown in your illustration from the dealer.

If it was mine I would remove the A-Frame first (because you already know that you have 1/2” of movement in the A-frame bearing, so it has to be fixed) and then try jacking somewhere under the frame to see whether or not there is movement in the hitch bearings. Personally I wouldn’t go into the hitch if it didn’t need it. I’ll see if I can post up a better parts drawing to make it easier to understand.

A question. How many total hours does the truck have on it right now.?

 

[Nige]

Here's a better Parts List of the Oscillating Hitch Gp with Part Numbers. Pin #10 is the one where the A-Frame beaaring/taper sleeve mount.

 

[chandler starling]

Nige, thank you for that better drawing. To answer your question about the hours. It has 13k hours on it.

So as soon as it gets to the shop, we will drop the A frame and hope that the bore hasn’t been damaged. Using the drawing that you last posted which parts should I go ahead and buy? I know that is a loaded question with out knowing the damage.

I don’t believe there is any movement in the Hitch bearings I am cofindent that it is all in the A frame.


Someone told me if you lift the bed all the way up and you feel the nose of the cab go down then you know your bearing in the hitch are in need of being replaced. I tried his idea and I felt no dip in the nose of the truck. Does that hold any truck?

 

[Nige]

To confirm it's all in the A-Frame I would still remove it first then put a jack under the nose end of the front chassis and slowly raise it while someone observes the hitch pins and bearings. What you've been told is probably right but if the bearings are only just starting to wear you will likely not feel it from the operator seat, you need to be watching the hitch closely while someone else operates a jack.

I've uploaded the file that the illustration in post #2 came from.
IMO lines 1, 4, & 5 you will definitely need.
Lines 14 and 18 (3 of each) you might need depending on what the existing hardware that holds the spherical bearing in place looks like when you pull everything apart.
Line 9A are the spherical bearings for the transverse link I referred to in post #7.

Oh, and here are the A-Frame removal instructions. I guarantee you won't have to do Steps 7, 8, & 11 because the bearing will be so loose you'll be fighting to stop the A-Frame failling off when you loosen the three bolts that hold the retainer plate on.

 

[chandler starling]

Mr.nige, I am so grateful for you. Can I just get you to come to the shop while I do this? Lol. I guess I will start order these parts and as soon as I can I’ll start taking that A frame out. You have really went beyond the norm to help me. I know for a fact that we can fix this problem now.

 

[chandler starling]

Mr. Nige

So we have started working on this ADT. The front cross member came out fine. But going to unbolt the A frame is when problems started to happen. I followed the directions that you provided me with. When we took the last two bolts out on the right hand side the whole tractor shifted. The axle ended up rolling. It pulled the drive shaft apart and is putting stress on the suspension Cylinders.


Well we stabilized it as is then continued to take the A frame off. I took the 3 bolts off the bottom pin which is supposed to retain a washer but I couldn’t find a washer.

So far this project has been overwhelming to say the least. Espically with this being my first rodeo.

 

[Cmark]

That doesn't sound right. When following Nige's instructions, how exactly did you go about

""Start By: A. Remove the stabilizer rod for the front axle. Refer to Disassembly and Assembly, "Front Axle
Stabilizer Rod - Remove"." ?

 

[chandler starling]

A-“Bait up” front axle with wood
B- support up A- frame
C - remove the cross member starting with the side that consist the bracket
D- drop crossmember
E- start removing A frame bolts on the left hand side- no movement
F- start removing right hand side A frame bolts . Bottom 2 came out easily with the 3/4 impact. But the top two wouldn’t budge with the 3/4.
Pull out the 1” impact. The top bolts start to come out but the axle is rolling forward. The truck is not moving just the axle.



Thank you cmark. Hopefully this will clarify.

 

[Nige]

I’ll be honest I would’ve chocked both sides of the front wheels before starting to unbolt stuff but I understand that it’s not standard practice for a lot of mechanics.

 

[chandler starling]

Do you think we have messed something up by allowing the axle to roll forward.

 

[Nige]

Difficult to know without photos.
Here is what Cmark was referring to when he asked about the removal of the Stabilizer Link.

 

[chandler starling]

So after reviewing the last posted article about the stabilizer rob.

We followed all the directions other than bracing the front of the machine with jack stands