Caterpillar D4C questions.

[OzDozer]

Each Cat engine from the early 1970's has a Serial Number that has a prefix, then a consecutive build number.

In this case, both your and my engine are "45V series" engine prefix - and my engine was the 29,120th 3204 engine built in that prefix series, and your engine was the 29,122nd built.

 

[1RJ01373]

Oh right ok, I understand it now.

Nige and Oz Dozer thanks, the amount of knowledge you guys have is incredible.
Now I can order the right parts for this thing

 

[Welder Dave]

Each Cat engine from the early 1970's has a Serial Number that has a prefix, then a consecutive build number.

In this case, both your and my engine are "45V series" engine prefix - and my engine was the 29,120th 3204 engine built in that prefix series, and your engine was the 29,122nd built.

The 2 engines were almost side by side on the assembly line. Interestingly I stumbled across a 931B with a serial number one less than mine and it was almost a completely different machine. Maybe made for a different market or something. I'm guessing Cat must have made some custom machines to the buyers specifications rather than just randomly putting backhoes and such on them.

 

[1RJ01373]

Hey guys, my left final drive was leaking, when I took it apart I discovered some wear on this gear. What would happen if I reuse it?

 

[Mcrafty1]

That looks like a LOT of wear to me, the pinion that drives it must not look much better? If you intend to do much work with the machine I wouldn't put that back in knowing it's condition nor the pinion (drive gear either) It may go a while but it may not too. It'll be much easier to change it now then after it's all back together and on the job. JMHO

 

[Nige]

Your photo only shows only one side of the teeth with a lot of wear. What does the other side off all the teeth that is hidden from the camera look like.?

What do the teeth on the mating pinion look like.?

 

[1RJ01373]

Here's the pinion. This is the one I really don't want to replace. It's a huge job

 

[1RJ01373]

Your photo only shows only one side of the teeth with a lot of wear. What does the other side off all the teeth that is hidden from the camera look like.?

What do the teeth on the mating pinion look like.?

The other sides of the teeth are pretty nice, I was hoping to just flip the gear, but it's not symmetrical

 

[OzDozer]

You can turn the bull gears over, but you have to swap from side to side. So that means dismantling the other side as well!
However, the bad news is - when you have two identical components, one each side - and you pull one down, and find it needs repair - then the other side is nearly always in identical condition!

That pinion is serviceable for probably 3000-4000 hrs of moderate work, provided you don't start doing heavy ripping!

 

[1RJ01373]

You can turn the bull gears over, but you have to swap from side to side. So that means dismantling the other side as well!
However, the bad news is - when you have two identical components, one each side - and you pull one down, and find it needs repair - then the other side is nearly always in identical condition!

This is bad news. The reason the left side has so much damage is cuz whoever assembled it last pounded the locknut on with a chisel. It requires about 800 newton meters of torque which is impossible to achieve with a hammer and chisel. So the locknut worked off, the bearing moved out of location on the sprocket shaft, so it then moved out of alignment, the duo cone seal got destroyed, and finally dirt went inside.

 

[Mcrafty1]

Here's the pinion. This is the one I really don't want to replace. It's a huge job
View attachment 294892

Surprisingly that pinion looks much better than the bull gear. What does the bearings/cones that you can see look like?

 

[1RJ01373]

The bearings and cones on the sprocket shaft are no longer serviceable, the gear side cone even came apart. The bearing that's inside the case for the pinion shaft is good, and the bearing on the clutch/brake case for the end of the sprocket shaft is also good.

 

[1RJ01373]

Based on what you guys are saying I'm gonna jack up the right side, check the right final, if it seems bad then I'll disassemble it and switch the gears, if it's good I'm gonna buy a new bull gear, part number 5G5847. I see it's about $750 on ebay, but I live in the Philippines so maybe $1000 after shipping and customs

 

[Dave Neubert]

Tightening the sprocket nut will not give you enough press fit you have to press the sprocket on with a cat press and if the sprocket presses on to where the spindle is sticking out past the sprocket you will have to change sprocket and maybe the spindle

 

[1RJ01373]

I'm gonna use a press to get those bearings on. Also I'll press the sprocket on since you can remove and install the entire final as an assembly, with sprocket installed.

 

[Drag racer]

Tightening the sprocket nut will not give you enough press fit you have to press the sprocket on with a cat press and if the sprocket presses on to where the spindle is sticking out past the sprocket you will have to change sprocket and maybe the spindle

Good luck finding a cat press not available any longer better find another solution

 

[1RJ01373]

Hi Guys. So my machine has been starting kind of weird lately. I'm fairly convinced that the starter motor is on its way out. My engine has been replaced with an older 3204, the serial number is45v29122, and some previous owner has converted it to 24v. I'd like to buy a new 12v starter and alternator. Would 7n4784 alternator and 4n0241 starter fit this engine.?

 

[Nige]

I would suggest first to take your starter motor to a good electrical shop and get a price for having it overhauled. You may find it is far more cost-effective to do that than go to the expense of buying both a starter and an alternator. Plus you may find that your problem might not be the starter at all...........

 

[1RJ01373]

Thanks Nige. That was my first plan. Then this guy quoted me $100 for that starter on Alibaba. So I got to thinking I'd better make sure about the part number. Found out later though he really meant $888 when he quoted $100. So yeah rebuilding looks pretty good again. Moral of the story: buying stuff on Alibaba is a crapshoot.

 

[Welder Dave]

I think it's been long established Alibaba sells poor quality parts.