oil pump lower idler gear adapter

[William Armstrong]

I am rebuilding my 350 B dozer engine. The oil pump lower gear oiler adapter that is mounted on the front of the under carriage prevents me from removing the front bearing cap. Manual doesn't mention how to remove it?
Any advice?

[Jim B]

I'm not following you when you refer to things being mounted to the under carriage. Are you doing this "in frame" or do you have the engine out? Been years since I was inside one of those. On a 4 cylinder you have to pretty much strip the front of the engine to get enough off to remove the front main bearing cap as there are capscrews through the front plate threaded into the bearing cap, whose heads are behind gears on the front side of the plate. Are you calling the block's front plate under carriage?

[LeonardL]

As Jim pointed out, I'm not sure I'm following you with the description you posted. If you are referring to the driven gear of the oil pump then your answer is "No" you can't remove the front main cap with it still in place. You have to remove the oil pump drive gear and remove the oil pump completely. It can be done in frame but is tricky to do and without the proper tools it is next to impossible to get the gear off without causing damage to the front cover on the engine. It is made of aluminum and will damage easily. This is why I don't recommend doing an in frame overhaul. If you don't know what you are doing you can screw things up and end up pulling the motor anyway.

If you have the motor out then you will need to first remove the front cover and then remove the oil pump. The drive gear is fitted to a tapered shaft and is friction fit only. Meaning there is no "Key" that helps the gear drive the pump shaft. There should be instructions in your manual on the procedure to remove the gear. I personally loosen the nut so it is flush with the end of the shaft. Then use a brass drift punch to strike the end of the shaft to get the gear loose from the taper. Then go ahead and remove the nut and gear.

[Jim B]

I did a bit more digging on this and looked for a 350B service manual on line. I found one (pretty poor as I didn't want to buy it), but in a preview I can see it has basically the same notes in several places as the 2020 (4 cylinder) manual I have. To service the crank and main bearings, the engine has to be removed. I believe what you are referring to as preventing the removal of the front main is the steel block, on the bearing side of the front plate, that the idler gear center bolt threads into. Leonard or someone may confirm this, but that block is fusion welded to the front plate as far as I know. That is why you have to strip the entire front of the engine and remove the front plate to get the front main bearing out. Does yours look similar to this picture and have a block like the one the arrow is pointing at?

[LeonardL]

Jim,
As I recall the three cylinder engines along with any non counter balanced Deere engine of the same style will not have the block you pointed out. Non counter balance engines have a bolt on the inside of the front engine plate that secures a short polished shaft on the outside or gear side of the engine plate. The idler gear then rides on this shaft. Some folks call this a pin or dowel rather than a shaft.
The bolt is in the same position as the steel block in your picture. This bolt has to be removed along with the oil pump to give the clearance needed to remove the main cap. To do this in frame is very tricky to say the least. I have done it but didn't like doing it because of the damage that can occur. As easy as these engines are to pull I don't even consider it as an option. The biggest reason is the time involved. The time it takes to do this in frame takes as long or even longer than it does to pull the engine and have out where you can get to everything.

[William Armstrong]

I did a bit more digging on this and looked for a 350B service manual on line. I found one (pretty poor as I didn't want to buy it), but in a preview I can see it has basically the same notes in several places as the 2020 (4 cylinder) manual I have. To service the crank and main bearings, the engine has to be removed. I believe what you are referring to as preventing the removal of the front main is the steel block, on the bearing side of the front plate, that the idler gear center bolt threads into. Leonard or someone may confirm this, but that block is fusion welded to the front plate as far as I know. That is why you have to strip the entire front of the engine and remove the front plate to get the front main bearing out. Does yours look similar to this picture and have a block like the one the arrow is pointing at?

yes,that is the block. I can tell from other posts that I have to remove the front plate to access those bearings. Thanks for the response.

[LeonardL]

Well I was obviously wrong then wasn't I!!?? I screwed the pooch on that for sure!! Sorry about that!! Maybe I need to quit commenting all together. It has been too long since I've been in the shop on a daily basis and am forgetting a lot of this stuff. Glad you sorted it out.

[Jim B]

Don't say that. I only knew about that as I have a 2020 (180 gas) open for a broken piston and found rolling the front main out in place wasn't practical because of the block for the idler mounting. The other bearing all looked very good and checked out ok so we are going to take the chance on it for now so we can run it and see if the rest of the tractor checks out as good as it seemed what I ran it before finding the broken piston. It is a recovery from under a barn that hadn't been run for years. Take care and have a good holiday.
Jim

[LeonardL]

Thanks Jim for your vote of confidence... I do appreciate it. What is bothering me a bit is the way I remember these motors. I really do not remember them having this block. But obviously they are there. I'm old... and I was just inside a 6329 six cylinder which is the same motor basically only with six cylinders. I should have seen this when I had that motor apart. I don't want to be the one giving out misleading information.