Main crank seal

[The Jug]

JD 3152 (m 43TF) I have main crank out and making parts list. On fly wheel end of crank there is a metal ring. I looked at parts book and it shows a seal #26-part number T20326 is that metal ring part of that seal? I Was thinking not but not 100 percent sure. I'm not able to find that part in parts line up. Maybe it shows it elsewhere?

[Jim B]

That is the wear ring used with the original type of rear main seal. I don't know the status of those wear rings and seals currently. The ones I have done the last couple years all ended up subbed to a unitized type of seal. The seal and wear ring are one-unit and you need a special tool to install them. The tool presses them in by pushing on both the outer part of the seal into the flywheel housing and the inner ring on the crank so as not to destroy the sealing between them. It also sets the depth the seal gets installed to. The new seals I have been getting for JD are part number DZ111672.

Someone may be along with some info on that original seal. Lavoy may have current info on whether or not you can get the original type of seal with the wear ring. I see dealer prices of $400 to $800 for the T20326 seal number. The dealer should be able to find out if you have to stay with the original type of seal or if the newer one will work.

I seem to remember seeing something about the flywheel housing needs to be enlarged to use the new seal on some early engines, of course I can't find it now. Looking at the online parts catalog there is a serial number break and the flywheel housing part number changes, along with the seal part number. And the newer housing with the newer seal is the sub for early T20263 housing, if one needed replacement. It looks like the cranks stayed the same. So, the machining the old flywheel housing to use the new type of seal looks like it may fit. Lavoy or LeonardL may have run into this.

Do you have the flywheel housing for both engines? If you do, mic the ID of the seal bore in both flywheel housings and see if they are the same. If the one from the later engine is different in the seal bore, you may want to use it to use the new seal. I would say mic the crank where the wear ring is, but I don't want you to remove the wear ring until you have correct info. You may need the number cast into the flywheel housing. Your dealer should be able to get the dimensions of the bores.

[The Jug]

Oh boy of course not what i wanted to hear but this is where I'm at. I'm going to keep moving forward on this. Some time ago I purchased a in frame rebuild kit from Lavoy. I believe we decided to go with the full rebuild kit so i would have parts if needed I think I have an oil ring that will work so I may just need wear ring and driver if needed. The oil seal i have is Maxi force TRE 44574. Also confirm with dealer that I do not need wear ring or i do need for this seal to work. I wonder if Lavoy could let me know if that seal will work with or without wear ring? Just to clear up confusion I only have one engine( M43TF my engine ) the 3152 was considering buying most likely would have ended up at this point anyhow , one old crank (crank is no good and has the wear ring on it and a new hate to say it a new aftermarket crank) I thank you very much and don't want to be too much of a pain by being lazy on my part, for i know where that will get me. Thanks again. So, to recap ill Mic out old shaft with wear ring. Then mic out new shaft, then fly wheel housing with that info see what i can find out from dealer. Hopefully have it settled. If that fails come back to place where I usually find the answers at. Please for sure let me know if I'm headed in wrong direction. Much appreciated.

[Jim B]

From a couple web searches, I believe the TRE44574 seal is an aftermarket supplier's part number for their seal to replace the JD RE44574 seal. The aftermarket uses several of the older unitized seal numbers to identify their seal. The John Deere RE44574 seal is a unitized seal, the separate wear ring is not used on the crankshaft. In the JD system that number has been superseded by the DZ111672 seal I used. So, you should be good to go as long as the seal OD is a few thousandths larger than the ID of the flywheel housing bore it fits in.

Do you have instructions for installing the seal? If not, while it is not a 3152 engine, this video will give you a good idea of the tool and how it installs the seal. There is a front and rear side to the seal, be sure you put it in right side to. The DZ111672 I use is labeled.

https://www.bing.com/videos/search?q=in ... ORM=VRDGAR

[The Jug]

-Wow that's great and clears up a lot. TY

[Jim B]

I will say I have been using Permatex High Tack on both sides of the gasket (R70483 which subs to R97351) that is between the block and flywheel housing. Replace that while you have the engine out, if you still have the flywheel housing mounted on the block. I had to split one ag tractor last year to replace that gasket and have another we just bought that is leaking behind the starter and will be getting a new gasket if all goes well this week

Run a tap or thread chaser in every threaded hole and blow/clean them out after. Not chasing and cleaning threaded holes can affect the torquing process. I use blue thread locker on the 8 capscrews that hold the flywheel housing to the block.

[The Jug]

I'm down to a clean block all steamed cleaned will dry and light oil to get things started. I will for sure run tap too through threads. I've herd of that before but didn't think it affected things enough to be concerned about. But I'll take all the advice I can get Thanks again! When setting main crank in place. Once caps are in place and cap screws finger tight what is the goal of tapping crank back and forth. Its stats to line up flanges. I took a look and could not see any difference. Maybe not looking in right spot?

[Jim B]

Chasing the threads in holes (and running the bolts/capscrews being reused on a wire wheel) is a good practice. If the threads are dirty, it may take more force to turn them which can lead to less torque actually being applied to the sealing surface/gasket. The other thing is cleaning the holes so the bolts/capscrews don't bottom out on crap in a hole stopping them short of fully tightening the joint. Holes need to be clean and dry, a light coat of oil on the fastener threads is all that is needed. Check around the top of threaded holes. Sometimes the top threads will pull a bit proud of the block surface and should be flattened down by hand if the block surface is not being machined. I have a Norton combination grit knife stone (about 2"x4") and a 1"x4" round Norton Crystolon combination grit bench stone I keep just for such, so the stones stay flat.

If the caps fit and set right, you won't see much difference after tapping if they were out of line the tapping may help them seat.

Use an assembly lube or Lubriplate 105 motor assembly grease. I used STP years ago as it was the go-to lube, however I use the 105 now. Th 105 or assembly lubes are better and allow turning the engine easier than STP. JMHO

[The Jug]

Good to know and I'll bet not often looked for. For sure not shown in any manual. I had the head worked on but not the block surface. I watched a full video on a full rebuild in a machine shop. Lots of stuff done there just can't be done in a small garage shop. So, we do what we can and doing the small stuff that we can do may make up some of the difference but not totally. After looking at what a shop rebuild will cost, one shop said 8700. Other rebuild was 6500 but don't know if he was same level as i am maybe a little better or could be a whole lot better but one never knows. At least ill know what i have done when i have finished. With lots of help i seem to be on the right track. Once motor is at the point i want it then ill move onto track frame. already in oil bath. every couple day.

[The Jug]

I will say I have been using Permatex High Tack on both sides of the gasket (R70483 which subs to R97351) that is between the block and flywheel housing. Replace that while you have the engine out, if you still have the flywheel housing mounted on the block. I had to split one ag tractor last year to replace that gasket and have another we just bought that is leaking behind the starter and will be getting a new gasket if all goes well this week

Run a tap or thread chaser in every threaded hole and blow/clean them out after. Not chasing and cleaning threaded holes can affect the torquing process. I use blue thread locker on the 8 capscrews that hold the flywheel housing to the block.

[The Jug]

Are you also useing it on front plate R73140 and timing cover T20155 ?

[Jim B]

I use High Tack on most gaskets. Normally I only put it on the component that comes off, so removal of the old gasket is easier. The flywheel housing is an exception where I do both sides.

I may be a bit OCDC, but I wipe the surfaces where gaskets go with a brake cleaner soaked rag, then once that has dried, I wipe with one soaked with 91% Isopropyl Alcohol. Sealants can really bite and hold on a clean surface.

If you were asking about the blue thread locker, I only use that on the 8-flywheel housing capscrews, unless called for by the manual in other places.