2120 Engine Rebuild Questions

[nokiddin]

Hey guys. I'm about to start assembly on my engine and have a question. I am sure I'll have more, so starting this thread in hopes to get some help.

First question, in regards to cylinder liner o rings. When I disassembled, I had 1 packing and 2 red o rings per liner.

My rebuild kit from Bepco, has a packing, 1 red o ring, 1 black o ring, per liner, with no instructions.

I will try to contact the company for direction, but was wondering if any one could comment on whether this will be a concern or not, and if I will need 2 red orings per liner.

Thanks

 

[Tx Jim]

I think red o-ring would go in groove above black o-ring

 

[nokiddin]

Next question. I have the gears all timed at the front, and I have the injection pump mounted. I don't know if I had to do this, but I checked the timing marks inside the pump. As far as I know, the A mark is supposed to line up with a mark on the snap ring, but there is no mark on the snap ring. I found a document online for roto diesel pumps and it said the A should line up with the inside edge of the snap ring. Mine is off about a 1/16th to 1/8 inch of that. I tried to rotate the pump body as the book says to line it up, but I cant rotate it anymore. Right now the pump is not straight up and down, but rotated a bit to the left.

How close does this have to be? The only way I think I could make it better would be to rotate the pump gear, but then my front gear timing marks will be off.

Any one have any insight?

 

[Tx Jim]

What method & tool did you utilize to set timing gears?

 

[nokiddin]

I used a fishing line with a loop in it to wrap around the crank shaft, then using a straight edge to ensure the line was in the middle of the shaft.

 

[nokiddin]

Are the pump marks supposed to line up at first piston TDC? Or just before TDC?

 

[nokiddin]

I judged TDC by hand. Is there a better way without a dial indicator?

I also read about timing gear backlash and I definitely did not over rotate and come back to adjust for that so maybe that's something else I need to try.

 

[Tx Jim]

I used a fishing line with a loop in it to wrap around the crank shaft, then using a straight edge to ensure the line was in the middle of the shaft.

That's a different method of timing the gears than I was aware of but it should be fine.

 

[nokiddin]

Yet another question.

The rear crank seal that came with my kit is the style that kind of has two rings and one spins inside the other (hope that makes sense). The seal that I took off the tractor is a single seal where the lip seals against the wear ring.

Is this intended to be a new improved style seal that I should use? Or should I send it back to get the other style seal?

 

[DLTrekkers]

That is the new stile seal and you needs a spesial tool to fit it.

 

[nokiddin]

Am I able to use it in place of the old seal? Is it an improvement?

Or do I need to get a different seal?

 

[jd110]

That is an improved design seal. If you buy from John Deere, it is the only choice available. Other suppliers may be able to furnish original style seal if you can’t obtain the proper tool to install it. On your earlier question about timing, when crankshaft is at TDC, there is a hole in flywheel that should align with hole in flywheel housing on left side that you can drop a pin or bolt into. Trying to visually guess at TDC of piston can result n several degrees off without the use of a dial indicator.

 

[nokiddin]

It turned that I have a friend who had a seal installer at work, so luckily I was able to use that.

Next up, I've been reading about setting the piston rings on first start up, and I was hoping you guys could tell me what I need to do.

I already have my pistons installed. I did not wash my new liners, but simply wiped them out, then lubricated the liner and piston /rings with 5w30 oil before installing.

The liners came with no instructions.

Will I have trouble with glazing if I didn't wash them? Do I need to pull them all apart to wash them?

 

[Tx Jim]

nokiddin
I recommend utilizing break-in engine oil during 1st 100 hrs of operation. If new rear seal happen to leak I be for changing flywheel housing or machining seal hole to accommodate later style/cheaper seal.

 

[nokiddin]

Thanks all for your help so far.

Just wanted to report that I finished up putting the tractor back together last night and was able to start it up!

I did decide to use the john deere break in oil. Any other tips on the break in process?