B7100 with a slight mechanical issue.

Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
Did you mark the flywheel and crank before you removed it?
The bolt holes are not the same all the way around, one is offset from the others, it's very slight but the bolts will not go in square if it's not lined up properly. ;)
Yes, everything is punch marked so it should go back together. There are factory markings on the flywheel for timing so I marked everything with 1TC facing the inspection hole on the bell housing.
 

Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
0
16
Tacoma, WA
Grumpy,

Glad the steering box is in good shape!

I happened to see this engine on eBay and thought you might be interested. You might be money ahead in the long run if you went this way. These engines are good for thousands of hours so I wouldn't be concerned about the time on it. The seller has been selling on eBay for a long time as I considered buying from him quite some time ago. I found an engine locally and that is why I didn't.

http://r.ebay.com/4PiIge

One note about the engines. If you look at your D750 closely, you will notice wires coming out of what would usually be the water pump. It's actually the generator on the D750. The US version of the D750 had no water pump, it used thermosyphon cooling. I do believe some of the UK versions of the D750 did come with water pumps, so it would be worth asking the seller about where the engine came from. However, it's not a show stopper either way. The D850 and D950's both came with water pumps as Kubota figured out they cooled better with them. The water pump engines have smaller diameter hose fittings than the original D750's, so it's just a matter of adapting the radiator hoses. One swapper simply bought hose that fit over the smaller connectors then slid the stock D750 radiator hoses over the top and clamped them. He mentioned it worked like a charm and he ran the tractor that way for years.

Also found these cranks out of 950's. I verified that the strokes between the D750, D850 & D950 are all 70mm. Since the blocks are the same, and the stroke between models is the same, it would make sense they might fit but I'm not sure because I've never tried it. Wolfman (or others) may know better if they interchange. Also, likely Grainfarmer (the eBay seller) would likely also know. He's been selling parts on eBay for a long time. Might be worth researching.

http://r.ebay.com/MGI6bb

http://r.ebay.com/gQzkuP

Finally, here are the rebuild kits I mentioned in my previous post. Not sure if he also has them for the D750, but it would be worth asking. He offers them with and without liners.

http://r.ebay.com/4vABy5

http://r.ebay.com/7ZHI9c

Good luck,

Steve
 
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Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
0
16
Tacoma, WA
Grumpy,

I bit of followup on the crankshafts.

Per the parts lists on the Kubota website, the D750 and early D950 both used the same crank. I'm not sure what the change was, but at some point Kubota changed at serial number <=369054 on the B7200 (D950). I'm **guessing** what changed was the pilot bearing size because I remember reading mention of that someplace. Or, they may have made a change to the front nose of the crank.

Pilot bearing hole size and front nose similarity not withstanding, I *think* you should be able to use the D950 crank as the journal and stroke measurements are the same.

Obviously take this with a grain of salt. The risk is yours if you choose to gamble on it. It might be worth asking the seller if he'd take it back if it didn't fit.

There ya have it...

Hope this helps!

Steve
 
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Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
Well I did not take the block, crank or cylinder head up to the machine shop today and I'll explain why.

I had a lengthy discussion with Apogee (thanks Steve) and we thought it would be in my best interest to can rebuilding this engine due too a number of reasons and no its not the end for this B7100.

We thought it would be best to source out a replacement engine instead so that's what I'm going to do.

That said, Apogee and I discussed a D950 swap and I believe that would be the best replacement engine choice.

A replacement D750 would cost me about $1,000 ready to drop in and go. A replacement D950 would cost me about $1,200+ any modifications.

I called and inquired about a used D950 and he didn't have any in stock now but would have a few by the middle of December.

I'm going to wait until he gets his shipment in from Japan so for now all I can do is clean parts and prep the tractor for paint.

I'll also be going through some of the D750 parts to see what I can sell to help offset the extra expense of the D950 swap.
 
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MagKarl

New member

Equipment
L245DT
Aug 2, 2010
663
0
0
Olympia, WA
I'm glad to hear you are going for the drop in. I checked the ebay links yesterday and based on those prices, I would have done the same.

Apogee, I hope I never find myself in major engine trouble, but I'm glad you are "local" and generous with your experience.
 

Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
0
16
Tacoma, WA
Good decision Steve! I think you will end up money ahead in the long run with more power to boot.

Since you have time, you might consider pulling the brakes apart and check to see how worn they are. Just a thought.

Magz, would be glad to help out if you ever find yourself in a jam.

Happy Holidays all,

Steve
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,203
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113
Sandpoint, ID
#1 change to the whole setup is hose size, the D750 you have is a siphon system where the D950 will have a water pump. You will need to take the necks of the radiator down to 1" size, I think they are 1 1/2 stock.

If you get a complete used unit, make sure it includes the alternator and alternator brackets. as you will not have a dynamo any more and will need them. There will be a little rewiring to make it work right but it's pretty simple.

The difference in the 2 cranks is the front of the crank, the 2 uses a different collar, seal behind the pulley and different pulley, really don't know why they changed it.

If you have a front pump or front clutch drive you will need to get the adapter to get back the splines of the older cranks.
 

Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
Good decision Steve! I think you will end up money ahead in the long run with more power to boot.

Since you have time, you might consider pulling the brakes apart and check to see how worn they are. Just a thought.

Magz, would be glad to help out if you ever find yourself in a jam.

Happy Holidays all,

Steve
Thanks Steve,

Yeah, I'll get into the rear brakes when I get it up on jackstands and remove the rear wheels. The brakes work perfectly but it wouldn't hurt to look.
 

Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
#1 change to the whole setup is hose size, the D750 you have is a siphon system where the D950 will have a water pump. You will need to take the necks of the radiator down to 1" size, I think they are 1 1/2 stock.

If you get a complete used unit, make sure it includes the alternator and alternator brackets. as you will not have a dynamo any more and will need them. There will be a little rewiring to make it work right but it's pretty simple.

The difference in the 2 cranks is the front of the crank, the 2 uses a different collar, seal behind the pulley and different pulley, really don't know why they changed it.

If you have a front pump or front clutch drive you will need to get the adapter to get back the splines of the older cranks.
Thanks Wolfman, I'm aware of the radiator fittings and having to relocate/rewire the alternator but I didn't know about the splines on the crank. The hydraulic pump for the FEL is up front so I'm going to need an adaptor correct?
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
Thanks Wolfman, I'm aware of the radiator fittings and having to relocate/rewire the alternator but I didn't know about the splines on the crank. The hydraulic pump for the FEL is up front so I'm going to need an adaptor correct?
Yes I do believe so.
 

Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
Yes I do believe so.
Great! I'll wait on sourcing out any parts until I've got a replacement engine here and that won't be until mid December at the earliest.

So parts that should swap over from the D750 to the D950 are the oil pick up tube, oil pan, flywheel, starter, exhaust manifold, intake manifold, rear engine plate, shutdown/throttle linkage and that's assuming I get the correct D950 and not a marine diesel.

If I'm not mistaken, the guy who I'm dealing with sells all of his engines complete with flywheel, starter, injection pump, injectors, alternator and cooling fan. Pending the location of the alternator on the D950 all I'd need to do is wire it in. Do the alternators on the D950 have a built in voltage regulator? requiring me to bypass and remove the original VR under the dash panel.

However, if I have to relocate the alternator from the side of the engine up to the top then I'll need the correct mounting brackets for that.

For the front engine pulley, I'll need the adapter to run the front pump with the original PTO shaft.

Coolant inlet/outlets are smaller diameter on the D950 verses bigger inlet/outlet ports on the radiator, easy enough to remedy.

This doesn't sound like a complicated swap to me at all.

Its a good thing I bagged and tagged every single bolt I removed from this tractor or I would have forgotten where most of it went during reassembly.
 

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North Idaho Wolfman

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Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,203
6,373
113
Sandpoint, ID
Yes you'll probably need your oil pan as you have a DT, the normal D950 pan is deeper and will not fit. The pick up tube is the same.

Shutdown and throttle on mine had to be reworked as the D950 has solenoid shut down on it, easy hookup and nice feature (key shutdown)!
 
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ShaunRH

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L3200
May 14, 2014
1,414
6
0
Atascadero, CA
That's super nice bagging work. I do a similar thing with the temporary Tupperware boxes you buy at the supermarket these days (I kept poking holes in the bags! DOH!). Did an entire lifter job on my Dakota and the boxes looked much like all your baggies there (worst part, turned out the issue wasn't with the lifters... again, DOH!).

Now I do that with anything that has more than a dozen parts coming off. Glad to see someone else with more discipline than even me!
 

Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
Just a quick update about what I'm doing with the sheet metal. Since everything is off I've decided the easiest and best way to clean these parts is to sand blast all of the sheet metal including the loader bucket, sub frame and chassis.

My dad was here and he took most of the parts with him and I will load the rest and head to his house Saturday morning. If the weather holds out and it stays dry we plan to sand blast everything we can. I am going to put a couple coats of etching primer on the parts we get done.

I was able to remove the grille from the radiator without busting off either securing stud. I also repaired the huge dent in the grille so its going to look goodwith a new coat of black paint. I was also able to get the hood and grille emblems off without breaking any of the mounting studs so its going to be easy putting them back on.

I will post pictures of all the parts before and after they have been blasted.

We wont have time to paint this weekend but I'm going back with the original colors on everything when we do paint.
 

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Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
Started media blasting this morning. Everything has turned out good thus far. I've used etching primer on the parts we've done and there is some slight pitting on the dash panel that will need some attention before it gets painted.

I'm losing every decal along the way and I'm going to try and source out some replacements and I know most of them are NLA from the dealer. I finally got my service manual too.

Here are a few pics...................
 

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Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
We got a lot done over the weekend with over 36 parts media blasted, primed and ready for paint. We have about 16 big parts left to do, hood, rear fenders, battery box, front sub frame and axle, rear chassis and the loader frame. We are going to save the front bucket for last because it needs some work.

Dad was able to remove a few small dings in the hood and we straightened out the rear fenders. We could have done more today but we ran out of blasting material. We can only recycle this stuff about 3 times but I'm very pleased how everything has turned out.

I'm going to check on the status of my replacement D950 this week and if its available I'll go pick it up, if not I've got plenty of hardware to clean up.

I'm still trying to figure out which FEL model I have so I can get a new breather/ filler cap for the fluid reservoir.

More to follow next weekend.
 

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