So earlier this week Helped Fourdaysoff Jim change out his defective ISL starter. 90k miles. So in thinking about this I decided to refreshen up mine with new brushes. Jims starter was cooked by ISL design. Solenoid failing secondary failure and would not turn over brush failure primary failure.
So I looked in to the 42MT bush kit. This has become a no value core being direct drive and Cummins has gone to a gear reduction starter that many here have changed too. Bushes were $19 , Holder was $219, rebuild kit was $49 plus all items were like $10 shipping each. Spent hours at work figuring out what I wanted to do and at the end of the day and hours of research threw my hands up and purchased a new Delco Remy 8200308 Genuine Starter Motor - 39MT 12V $275 starter delivered to my door step. I generally prefer to repair stuff but felt like it was not cost effective too.
The advantages are many. 30 lbs lighter. Supposedly reduced amp draw during start. Finally removing weight off the fat coach, but will add in other places deemed necessary.
Anyway I'm going to do a amp draw before and after and hopefully have some real world numbers to help justify the hopefully upgrade. Will include voltage and the temperature numbers.
More too follow.
Will have a real nice slightly used (70K) 42MT starter available if some one needs. You pay shipping. 59 lbs lol
Translated: Soon to be unavailable.
You will like the new starter. Make sure the cable connections at the starter are clean and tight. Then check the two studs on the back part of the battery reach frame and all of the connections there. My studs were corroded and overloaded. I couldn't loosen or tighten them. Consider replacing them. I used three stud bus bars.
My studs just snapped off when I tried to loosen them. Ended up replacing with BlueSea.
Rich
Ill order some posts once I figure out what I want. Yes they also have a service life, but a 1/2 bolt and a roll of tape would get me home for repairs. Currently voltage drop across posts is acceptable. Starter operation with the 42MT is acceptable. Broken down at the fuel stop is not acceptable. Figure its just getting ahead of a inevitable problem. That being said it probably has a 1000 starts available, who knows. Just being paranoid probably.
I would like a gear reduction starter ^.^d
You will love it. Will make that lump bust off in only twice the crank time of a C8.3. :D :D :D
Sure made my M-11 start so much easier. My engine turned over so slowly that it was as if I had perpetually flat start batteries. Not any more.
So getting a head start on my started swap pulled coach in front of shop and put up on blocks. Pulled work carpet under the rear and pulled starter. 5/8 12 point socket mount bolts. The easiest bolt to get to is below the retarder mount and is the only one with exposed threads on back side facing forward. Well over the years of road exposure the threads required wrenching them all the way out. Threads looked like crap. So I took a 5/8 NC 11 tap and was unable to get a clean start into threads. So started tap on back side and was able to run thru threads to clean up. I believe there is enough good threads to make torque. Point being on your ISM you have the same set up. At the very least fill the threads full of grease or silicone seal to prevent any more road filth accumulation. Ready for install other projects to tend to.
Scott
Almost looks like they have been heli-coiled
Would of been nice, but no . Cut into aluminum casting and torque was so hi it sends a spike threw my damaged spine when breaks free. Way more than 250 ftpounds to release. Helicoil was my first thought till it cleaned up pretty good. Possible it was crossthreaded prior? It was second removed and was belligerent for every turn out. First and third were equally tight but once free would run out by fingers
When I had a 8.3 mechanical it started as soon as the first cylinder got to top dead
center, until it got below freezing and then then it was slow starting and a gear
starter would have been nice. The M11 I have now turns over really good and it
starts below freezing good but if the starter went I would put a gear starter in as
the faster the engine turns over the better.
I actually thought of you and your adverse operating conditions. Nothing to do with the gear drive as much as it is the corrosion of that outboard mount bolt. Lube and seal for future success in replacement. Glad I did at home not in the fuel line of a truck stop.
I'm really happy how this engine starts in the cold.
I'm just saying spray and seal that one bolt to enable removal in the future
Attempted to record amp draw but my meter is too small. On the three batteries the last one showed 275 amp draw, guessing that is 1/3 the draw . Will compare with new starter
Just got back from Q. The upgraded starter Scott help me change works great. No difference between boost switch or not. Previous starter I always used boost, without it cranked like it had poor chassis batteries. Jim.
Hard to describe the difference between the old and new. Oh wait 28 pound lighter.
Easy install. Cranks muck faster. Hardest part was twisting that small solenoid wire and installing. Took more time that the entire installation. Amp draw in same position went up to 407 amps? Too many variables either way it started better and it's new. Did entire install from under coach.
Scott
DSD
Would that be the SAME starter for my 1998 U 320 with an M11 engine?
Interested as I use the boost ALL the time. With just the start batteries it seams weak.... (reference a previous post...)
So Peter you bring up a point I had not addressed. My three group 31 batteries were new may 2020. My cables are in good condition and were modified to ring lugs and 3/8 battery posts with nuts. Ive never used the Boost solenoid since I left Arkansas when I picked up my coach. It has always started well and the coldest temperature down to 22.0 deg F without preheating engine. I was curious and very surprised with its low temperature starting. IMO if your needing boost to start something needs to be addressed. Extreme low temperature, weak batteries, poor cables, grounds, failing starter, air leak in fuel?
I'm guessing it is, always best to check with Cummins
Cummins QuickServe Online (https://quickserve.cummins.com/info/index.html)
Delco Remy 8200308 Genuine Starter Motor - 39MT 12V - New No Box | eBay (https://www.ebay.com/itm/393696802244)
Currently no stock
Mine started at at 21 F this morning with no heat. It took a few more revaluations
than usual. Lower than 14 F I give it heat. At below 0 one hour seems to be enough
from the Aqua-hot.
This morning it is -8 C 17.6 F and I noticed the start batteries were at 12.2 and as it
wasn't starting and I hit the boost switch and it started right away. My house batteries
was higher than my start batteries which never happens so maybe the start batteries
are starting to fail or there is a draw on them. The start batteries are usually at 12.8
before starting.
Parasitic draw on the start batteries on most vehicles and I don't think our coaches are the exception.
I think I found the problem with my start batteries, they were dirty on top and I think
that was what was discharging my batteries. I haven't done a voltage check on the top
of batteries for years but I was getting over a volt and a half on the top of my batteries.
I will know for sure when I go to Whistler next.