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Gear Reduction Starter Replacement LM318's

piper468

Contributing Member
Here is a picture of my old Prestolite Starter with a ruler that shows the position of the drive gear.

starter bendixmsrmnt.jpg

Here is a few pictures of the new gear reduction starter that doesn't engage the ring gear.

Starter Drive Gear Travel.jpg

Starter Engagement Dimension.jpg


These starters won't work on my engines but they do on some others. What's the difference?

Russ
 
More info: The new gear reduction starter comes from Rare Electrical and they claim on their website that they are direct replacements for the Prestolite MDT7022.

http://www.rareelectrical.com/p-143...60-1971-acadia-marine-inboard-sterndrive.aspx

I've heard that others have used this starter on the LM318's without any issues. I'm not sure what's different with mine. It's either the starter or something to do with the flywheel or bell housing. Does anyone out there have LM318's with the starter mounted on the back of the bell housing facing aft? If so what part number starter do you use? How far is the flywheel ring gear from the starter mount on the bell housing? (see photo below)

Bell housing to ring gear.jpg

Maybe just maybe we can get to the bottom of this. Thanks

Russ
 
Russ, here are a few suggestions that may or may not be realistic, and they may be long shots.
I thought I'd toss them out anyway.



  1. By chance is there a thin spacer plate between the flywheel covers and the engines? (very long shot)
  2. Are the flywheel ring gear teeth all there and healthy?
  3. Are the flywheel ring gears in the correct positon on the flywheels?
  4. Are the old Prestolite Bendix drive motors extending the pinion gears further than need be, causing your comparison measurements to be off?
  5. Is there a chance that new HTGR motors have the pinion gears/shafts reversed (re; armature rotation/direction), casusing non-function of the "kick-out"?

As per #5, these new starter motor pinion shafts may be spiral splined (similar to the Bendix idea) causing engagement, in lieu of solenoid lever action.
If so, and if these were accidentally reversed (as per starter and engine rotation) during assembly, the splines would not allow the starter motor rotation to kick the pinion gear out.

Read the Autocosmos PDF page #13, item "I" under the heading "Bendix-Drive is Slipping: "
This can also occur with the spiral spline scenario if these are reversed.


BTW..... what the Autocosmos people are calling rollers, is actually a form of sprague or sprag clutch.
images
 

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Hi Rick,
I know that there's no spacers between the flywheel covers and engines, but that was worth a look at. I haven't looked at the flywheel ring gear teeth all the way around but I'm assuming there OK because when I put my old direct drive starters on they turn over just fine. No grinding or chattering noise. #4 is also good to check. I measured from where the starter mounts on the flywheel cover to the aft face of the ring gear on the flywheel. See picture. Both engines are the same measurement. The starter drive has to extend out to the 2" mark for it to fully engage the ring gear.


aftringgeartobellhousemnt.jpg


When I bench tested the new HTGR starters they both kicked the drive gear out to it's full travel. But they need to go 3/8" more to engage the ring gear. They also turned in the direction as indicated CW and CCW. I already sent them back to Rare Electrical so I can't tinker with them anymore.

Do you know where I might find Gear Reduction starters for my boat? We both live in the Portland area so if you know where I can look for replacements please let me know. Thanks


Russ
 
OK Starter issue resolved. It was the starters I ordered from Rare Electrical. On their website they claim that these starters are replacements for the Prestolite MDT 7022 and MDT 7021. Well they're not. After weeks of research I found a company in Florida called API Marine. Great service. I talked with one of their salesmen and described the issue I had with my starters I purchased from Rare Electrical. He told me that they sell cheap China imports and that's why they cost $300 less. Originally I didn't want to purchase the more expensive starters from API but I caved in and bought them. I wasn't going to spend the money until I knew that they would work. The guy at API walked the starters down to the engineering department and they got an accurate measurement of the pinion drive gear travel. I've attached the photos that I took so you can see what I'm talking about. Basically the API starters have about 3/16 to 1/4" more travel. I haven't been up to Alaska to try them out but I'm sure that's the problem. I'll post an update after I get them installed. Don't buy from Rare Electrical, It took me two weeks and 4 or 5 phone calls to get my money back. The BBB gives them a D- rating.

Cheers

Russell


llNew Starter.jpgNew Starter Engagement.jpg
 
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OK Spring is here and these new starters from API Marine are the bomb! They crank my motors over like there's no tomorrow. I will never go back to my old direct drive starters again. For the price these new starters are spendy but on the upside they have more torque and are much lighter. I can hold them with one hand when installing. They also come with the relay so no more external relay with wires going everywhere. Best investment yet for my boat!

Russ
 
Old thread, but I just want to point out that API Marine no longer manufacture CCW rotation starters for Mopar. I spoke to them a month ago, but they were kind enough to point me in the direction of Hitorque in California. I spoke to Chris who supplied me with a great Hi Torque CCW starter for my 440 engine. Works great!
IMI-126-001 (003).jpg
 
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