Too much ambition, too little knowledge

[raklet]

Anybody ever have the intention of only starting a small project but end up turning it into a huge one? Now, I'm in that sinking boat and need a bailout (well some knowledge at least).

I started out wanting to do an electric start conversion on an 8T motor grader and upgrade the moldboard to hydraulic sideshift.

The electric start is no problem. Many people helped me out in telling me what to do - with a large portion of the thanks going to Old Magnet and Josh.

The moldboard is where I started to take larger and larger bites. I was going to do a home built conversion on the stationary moldboard but didn't really like how it was shaping up. While buying repair parts for my 8T at a salvage yard, I came across a 70D motor grader. Not only does the grader have hydraulic sideshift, it also has better power steering, a better frame, and much more. It does have lower engine problems, so it doesn't run, but the price to buy the whole machine outright was so ridiculously low that I decided to buy the whole thing.

Now, here is where my ambition has overtaken my knowledge. I decided I would pull the engine out of my 8T and put it in the 70D. It sounded like a good plan - new frame with all the upgrades I want, just needs a new engine. So, I have the engine out of my 8T (that went well with no problems) but I am looking at the bell housing on the 8T compared to the bell housing on the 70D and they appear to be different.

Now for the questions.

* Am I going to have to change the ring gear housings so that my 8T engine will fit in the 70D?

* If I have to change the housings, what bolt size and thread do I need to release the pressure on the clutch?

* Where can I get an alignment tool to put it all back together?

* Will the 8T engine even fit in the 70D or did I screw myself?

I think that's it for now. Any help would be appreciated.

Thanks,

Tyler

[Old Magnet]

Well, ya got in good this time
The 70D is an oil clutch model that uses a different bellhousing, engine oil pump arrangement, pan, flywheel and crankshaft and in the seat starting of the pony motor.

The basic engine is the same but the main crankshaft is a different part number along with the flywheel. Even the ring gear is a different number although they are both 112 tooth.

Your looking at some major work to convert and if the lower end of the 70D is bad there is no easy fix there.

If you were to convert from oil to dry clutch you would be in the same fix trying to get to direct electric start.

[raklet]

Well, ya got in good this time
The 70D is an oil clutch model that uses a different bellhousing, engine oil pump arrangement, pan, flywheel and crankshaft and in the seat starting of the pony motor.

The basic engine is the same but the main crankshaft is a different part number along with the flywheel. Even the ring gear is a different number although they are both 112 tooth.

Your looking at some major work to convert and if the lower end of the 70D is bad there is no easy fix there.

If you were to convert from oil to dry clutch you would be in the same fix trying to get to direct electric start.

Plenty of curse words go here. Yep, I got in good. Plan B - put the engine back in the 8T and move as much of the stuff from the 70D over to the 8T as possible.

How about the transmission in the 70D? Will it fit in an 8T? A friend has an 8T with a bad tranny and would like to split the cost of this purchase with me if he can get a tranny out of the deal.

[Deas Plant.]

Hi, Raklet.
While I can't go into specifics about what will fit and what will not, you ARE looking at 2 graders whose development is around 20 years apart. The 70D is somewhere around 35-40 horsepower more than the 8T and maybe as much as 1 1/2 - 2 tons heavier. As Old Magnet said, your 8T is a dry clutch and the 70D is an oil clutch. The 70D came designed to have hydraulics pretty much standard as power blades (side-shift) and rear rippers were very common attachments on the later machines. Power steering design had gone through several generation changes and even the internals of the control gear boxes had been upgraded.

The transmission had gone from 2-speed reverse to 4-speed reverse and 4-wheel braking on the drive axles was pretty much standard as opposed to the standard 2-wheel braking set-up on the 8T. (You had braking on all 4 drive wheels on the 8T due to the connecting chains in the chain cases but brakes were standard on only the 2 rear wheels of the drive.)

If the engine is the only problem with the 70D, I'd be looking at the cost of fixing that. IF that proves prohibitive, then and only then would I be thinking of stripping stuff from it to put on your 8T. It may work better to look for a donor engine for the 70D and sell your 8T to your friend as a parts machine for his jigger. I doubt the 70D transmission would fit easily into his 8T for the same reasons that you are having trouble mating the 8T engine to your 70D frame and transmision.

Keep asking questions, M8. You'll get all sorts of answers from all sorts of people. Then, YOU have to decide what to do AND do it. All part of the fun. LOL.

[Old Magnet]

As usual there are variations in specifications and statements
Don't know about 20 year difference (maybe the technology)....the 8T was produced from 1947-1957 and replaced by the 70/71D which ran from 1957-1959 or 60. Granted there are quite a few upgrades to the 70D.
I show the 8T as 100 brake hp and weighed 22,200 lbs.
The 70D at 115 brake hp and 23,155 lbs.

Looking at the transmission gears vs speeds they are the same but that doesn't necessarily mean they are 100% interchangeable and a one for one parts comparison would be recommended before attempting interchange.

I can visualize three machines apart and some serious head scratching
Good luck with the puzzle.

[raklet]

Thanks for the info OM. I'm feeling a bit better about the situation now. I really think I can move or adapt a lot of stuff from the 70D onto the 8T. If the transmission from the 70D will fit into an 8T, that's a bonus. Then perhaps I can sell the rest of the machine for parts and I won't be any worse off than I was before.

[Old Magnet]

Could you post the serial numbers of all three machines you are dealing with?

[raklet]

8T 264 (mine, want to upgrade power steering, moldboard, etc)
70D 3819 (donor)
8T 1238 (friends, bad transmission)

[ccjersey]

Like Deas says, the engine swap/repair will be the most rewarding. If you can get the 70D going, you will have all the improvements both large and small over 10-12 years of grader production in your operating machine. Of course you may find some hidden problem when you have power in it.

I would get casting numbers etc off the blocks, compare gasket #'s between engine and clutch housing for both machines, front mount isolator part numbers etc. The crankshaft number might be different because of the higher hp on the later engine (higher rpm/vibration damper???? etc and have the same dimensions on the flange end so the older engine would bolt right up, or it might have different dimensions for the oil clutch/flywheel attachment.

Is it possible the 70D used the redesigned higher hp D318 Industrial which came out between the old D318 and the D333?

[SJ]

Someone put a short one on one of the sites and it said "Experience is what you get just after you needed it".CC the only higher HP D318 I can remember is one that,s turbocharged but with the NA engines there were many rack and RPMs and governor settings and gov. springs for them which changed HP and for what it was used for or in.