Does anyone have any idea how much it takes to change the flywheel on a Caterpillar 428 backhoe from the 80’es ? regards Rix
With a machine Serial Number I'm sure a disassembly/assembly procedure could be found. Can I ask why you are planning to replace a flywheel.? As a wild guess - starter ring gear damaged.......
Yes your right, is that a normal thing that happens ?
Flywheel ring gear teeth do wear out over time, that's why they are replaceable separately. See attached. By the looks of it the engine, torque converter, and transmission all come out together and have to be split once they are out of the machine. I will find a procedure for that and post it up.
Post a picture of the ring gear damage as maybe it can be repaired sufficiently with a die grinder and carbide. Of coarse if it is too bad, then follow the R&R Procedure as per Nige's post. Simon C
I only have this picture. They look pretty worn down…. It only where the starter insert the wheel.
I have broken the axel of 2 starter now and am afraid a new one will break too.
Unfortunately that ring gear is well past the stage of resurrection. At least now you know that you don't have to change the complete flywheel to replace it. I think it's time to remove the engine and install a new ring gear. i have attached the basic procedure. If you require any more detail about any of the other parts of the procedure that are not shown, please ask.
Not a real bad job if you have a transmission jack. you will have to block machine pretty high to get transmission out from under machine. I can't remember if we used 12 inch or 16 inches of cribbing under the tires Important note leave outriggers and bucket on ground as you are removing parking brake wheel chocks would be a plus too. you will have to remove drive shaft, parking cable wires and fill tube. Their is a plate under bell housing with 4 bolts remove it you will have to use a pry bar to turn engine to access bolts that hold convertor to flywheel you will also need to remove gear shift and floor plate over transmission
So the whole engine needs to come out? Isn’t is possible to push the converter back, just enough to get tools up and loosen the flywheel?
Sorry, that one does not meet the criteria for die grinder miracle. Now we know how bad.
Two different starting motor shafts broken and a badly damaged ring gear ? That is a strong indication that you have either the starting motor installed or most likely it has the wrong Bendix Drive gear on it. IMHO of course. I went through the very same situation a few years ago.
So you suggest the starter is wrong somehow?
No. he is suggesting it is a possibility and that you should take a close look at the gear on the end of the starter shaft and count how many teeth it has. According to the information I found it should have 11 teeth.
I would think the shaft breaking would be caused by bendix gear being forced up caused by worn out ring gear teeth ie the bendix trying to jump worn out teeth
Ahhh, okay. I love to hear every aspect and view on this, because then chances are I get it more correct… and since I need to take out the engine I’ll need to keep my eyes on everything so when it comes in everything is replaced/ fixed and it’s good to go.
also sounds possible.
The problem I had, was a Bendix gear that too many teeth. It applied a huge amount of pressure against the starting motor shaft when it was engaged. I found two broken off starting motor armature shaft ends in the bottom of the bell housing when I removed the engine for an overhaul. That is what alerted me to something that wasn't quite right with the starter. Strangely the starter turned the motor reasonably fast, but it made a nasty growling sound. Like Nige said, I'm not saying that is your problem. But, I strongly suggest that you eliminate the possibility's I suggest. Sadly I badly damaged a new ring gear before I determined the Bendix gear was the cause of all the problems. There is also a remote chance that your ring-gear has the incorrect number of teeth.
Okay, even though I got the starter from a guy who does this for a living, looked around for the right starter, I’ll question this to make sure its the correct one. The ring-gearing im not sure about because I think ( I’m not sure) it was never replaced.
If he sold you a starter that matched the old one, the chances are quite high it isn't a match to the Cat OEM one that came on the tractor when it was new. Count the teeth on the old ring-gear and the replacement one before you install the new one. It would be nice if you knew for sure how many teeth the OEM one has. Are you getting an aftermarket ring-gear ?
The OEM ring gear has 115 teeth according to the 7W6212 attachment in Post #4.
I’ll be counting a lot now for sure I hope Nige can tell me, and I’ll see what we can get. One or aftermarket, I’m not sure yet…. the price will be a factor to think about too, because it’s not cheap here. I just saw Nige posted it !
Now I want to thank everyone who helped with this and if there is more I should know or think about, please do tell.
Does anyone know if this part is available in Europe ? The ring for the flywheel 7W-6247
Try searching on eBay UK site. Using the 7W6247 Part Number I found quite a number of options like this one.
Cool Nige….. so do you also have a number for the sealing behind it ? I think it will be smart to change that too.
Do you mean the rear crankshaft seal.? I did look and am not 100% sure that I am looking at the right part.
Yes.
I think it could be #20 on the attachment. I hope someone can confirm that plus shed some light on the replacement procedure for it because I see nothing. That should not be taken as implying that it is simple to replace.
(20)4w5360 and (21)6n9322 gasket I remember having to take aluminum housing off to change the seal Gasket is for housing
So is it possible to just screw it off, replace the gasket and seal and screw it together again ?
Does anyone know if we can take off the converter without the oil running out ?
Do you know if we can take off the converter without the oil running out ?
Or do you know if we can take off the converter without the oil running out Nige ?
Sorry no idea. Never done one. Maybe @pittsburgh cat man can advise.?
You will get some leakage after you pull it off set it transmission side up
Thanks !
my friend who helps me told me everyw he looks it says 10 teeth ?
Attached the parts breakdown of the starter motor that SHOULD be installed on your machine according to the machine Serial Number. If a replacement aftermarket starter motor has been installed at some point then all bets are off. The damage to the flywheel ring gear strongly suggests that the pinion gear of the starter motor that was installed on the machine has the incorrect number of teeth. All the indications I have found suggest that the 9W-0850 drive clutch pinion has 11 teeth. However I may be wrong. At least now you have the correct Part Number to search for.
The engine is out and the converter is off. he counted 115 teeth on the flywheel, so at least that’s the same. he told me yesterday that he will try to put on the starter and see how it goes into grip and how it fits now. About 25% of the teeth is missing.
Have you fitted a new flywheel ring gear yet.? If not then what he proposes might give you some indication if the pinion is correct or not. I am sure the starter pinion teeth must also be damaged. Are you not planning on buying a new one.? If you purchase it based on the Part Number (assuming your starter motor is still OEM Cat) then it should be the correct one.
No the old one is still on. We want to be 100% in line with everything before we buy anything so we don’t mix up or damage anything.