STARTER FOR 8V-71 with MT654

[Stormcloud]

Good day:

While we are changing the 4 speed Spicer for an MT-654 automatic, I thought I should get the starter 'freshened up'. The drive is worn and chipped.

The rebuilder says to check the # of teeth on the original starter for the automatic to make sure. ( I never thought that they may be different!)

I have a message away to the auto transmission's former owner, and have asked Luke also. Luke hasn't had a bus starter with other than 11 teeth on these old Detroits, standard OR automatic.

Anyone out there with an 8V-71 and MT654 confirm on their spare starter that the drive is 11 teeth?

Thanks!

Mark

[bobofthenorth]

I'll put in my annual advertisement for an MT39.  You're a big guy but even you would appreciate how easy the MT series are to handle and they're not expensive.  Maybe less than the cost of rebuilding your 42 series.

[Stormcloud]

I have been thinking of getting a spare starter, and I know you have one of the 'featherweight' versions which I would probably look for.

But not until I know for sure how many teeth.

[lostagain]

Mark, I went to look at both my spare starters. They are both 11 teeth, including the one for the 6V92/HT740. I know not a match to your 8V71, but an indication nonetheless.

JC

[luvrbus]

The 600  and the 700 series are different one has the starter ring gear on the flywheel the other on the torque converter and it all depends on the ring gear some 8v92's have 12 or 13 tooth starters and 24v or 12 V come into play,10 tooth are usually found on the 37mt or 28mt Delco starters fwiw

good luck

[fraser8]

When my starter went, the local parts supplier had one on the shelf (lots of logging trucks in the area) we just matched them up side by side and I paid $135.00 for it. He was happy to sell some old stock.
See you in August

[Stormcloud]

The ring gear is on the flex plate in this instance. 118 teeth to be exact.

I'm kind of expecting/hoping its 11 tooth, as Luke suggested, but I'm waiting to hear about the original starter.

Thanks for all the replies so far!

Mark

[Stormcloud]

Update:

It seems in order to install an automatic transmission on an 8V-71, it needs to have an SAE1 bellhousing. The standard transmission which was OE on the bus uses an SAE2 bellhousing. The 'new' flex plate fills the hole in the SAE2 but leaves no room for the starter...hmmm.

My 'old' bus mechanic to the rescue.....he has a bellhousing from a 6V-92 just laying around. Imagine that!
All the holes line up ( with the exception of the crankshaft hole being too large), and there's a gaping hole for a gear drive alternator (which I don't have). My old 4-belt alternator will not work with this housing, so a new 105Amp 24 volt alternator is on the way. Also, my starter rebuilder called with the bad news. Starter has a bent armature, and is in general fairly poor condition. I ordered a rebuilt from him which should be here Monday, and he's keeping the old one to patch up as a spare for me ( he occasionally gets starters in that may have a repairable armature).

I have arranged for a machine shop to make up a seal adapter for the 6V-92 bellhousing to accept the 8V-71 seal, and I made a blockoff plate for the unused alternator holes. The machine shop will also take out about 6.65 inches of driveshaft and balance it because trhe automatic is a bit longer.

We need to modify the rear engine mounts because they fit about 4 inches higher on this 'new' bellhousing.....the mechanic working on this with my is very familiar with the old Detroit engines, and he's an excellent fabricator, definitely a good guy to know and have his cel number on speed-dial!

It appears that I found the source of the most serious oil leak. A piece of gasket from the air compressor to accessory housing broke loose, and oil was splashing up onto the blower housing at the rear of the engine and tracking forward (rearward).

We are replacing all the gaskets on the rear of the engine, and the blower gaskets too. Timing gears have been left at standard timing, because the bus runs so well as it is, I don't want to mess with it.

Spent the day cleaning the drive housings, motor mounts; tomorrow, drop the driveshaft.

I'm also gonna paint the engine when its ready to run......anything but green!!!

[luvrbus]

You need a drop ring and the 15/16 in spacer to make your bell housing work

[fraser8]

Mark, paint it John Deere green and I'll give you a JD emblem for the back. Any tires yet?

[Stormcloud]

Not green of any shade. Don't want to encourage leaking.   

The buses sold to the local metal scrapyard this year. I will call there this week to see if there are any tires of the correct size; how many are you looking for, just in case.

[bevans6]

Clifford, can you expand on what the drop ring and spacer is?  I suspect the spacer is between the bellhousing and the transmission, to move the trans back to make room for the torque converter, but I can't imagine what the drop ring is.  I ask because I have the SAE #1 bellhousing left over from my military engine adventure, and I have kept it so far thinking it's value as a potential aid to a MT640 trans swap outweighs it's value as a large chunk of salvage aluminium. 

Why can't the belt drive accessory drive be installed on the 6V-92 bell-housing?  You'd have to take the bell-housing off anyway, and you should be able to swap over the cam drive plate no problem, in the same position as the gear drive for the gear drive alternator is now?  In any case, a complete 4-belt drive assembly plus a belt drive 50DN alternator would seem to be a valuable spare part for people who want to do away with their gear drive alternators but retain the big high current alternator - or just get a handy belt drive on the back of the engine!

Brian

Brian

[luvrbus]

A drop ring is a adapter ring it drops the sae 1 bellhousing down to sae 2 for the 500 and 600 transmission, 

I can't wrap my brain around what he is trying to do the 600 series is not a direct bolt up to a sae 1 bellhousing it is for the sae 2 

I am missing something here lol

[Stormcloud]

I may be using the wrong terminology, so here goes again.

The 8V-71 had a steel cover for all the works on the back of the engine ( accessory drive cover?) and the transmission bolted up to this with the clutch inside the bellhousing that came off with the transmission.

The accessory drive cover hole big hole around the crank was large enough to accept the flexplate for the MT654, but the flex plate was large enough that it almost completely covered the hole where the starter drive enters to engage the flexplate.

A 6V-92 cover was checked, and it bolts on the 8V-71 but there are a couple of problems...
1) The original 225Amp belt-driven alternator won't work on the 6V housing. It is machined for a gear-driven alternator.
2) The crank seal hole in the 6V housing fits a 92 crank (which has a larger diameter seal). An adapter is being made to allow an 8V seal to fit this hole.
3) The 'cradle mounts' that were attached with 6 bolts on each side of the 8V accessory housing are attached fairly low on the housing. The mounting points on the 6V housing are much higher. We are modifying the existing mounts to allow for the additional height and maintain the same relative position on the engine cradle.

The MT654 will bolt  to the adapter ring which in turn bolts to the 6V-92 housing. We have a hub which bolts to the crankshaft and the flexplate to set it at the correct distance from the block. Driveshaft has to be shortened by about 6.5 inches to fit.

I think I have this all explained correctly.

[fraser8]

Clear to me, sounds like another job where you get hair loss.