Delco to Denso starter swap

[Mike D]

My 2005 T-S Select wouldn't crank over. After I determined that the starter was the problem I decided to replace the original starter with a Denso gear reduction starter.

The engine is a Cummins 500 HP.

The O.E.M.starter was labeled in it's ID tag as a Cummins part # 3103304. There was also a Delco part number on the tag (8200694). It was a Delco MT39 starter and had never cranked over all that great,especially after sitting for some time.

The Denso web site's cross reference showed no Denso equivalent to either the Delco or the Cummins parts numbers. I spent some time on IRV2 researching what others have done and determined that the Denso TG428000 4430 was the best shot.

I bought a new Denso starter (TG428000 4430) but when put side by side I found that the Denso starter had a 10 tooth drive gear vs the Delco's 11 tooth drive gear. Both starters had the same pitch gear teeth (6/8 pitch) but the Denso was noticeably smaller.

I made some careful measurements of both starters and found that the Denso's drive gear was offset closer to the engine vs the Delco's drive gear. I was able to determine that the Denso would engage the flywheel as fully as the Delco starter drive gear.

Other than that issue the starter looked like a good fit. As installed the Denso's solenoid was on top of the starter, same as the Delco/Cummins starter and the drain vents on the Denso pointed towards the ground as they should.

I went to the Delco Remy web site cross reference and found that the Denso starter crossed to the same replacement part number as the Cummins and Delco part numbers crossed to.

I installed the Denso and it works perfectly. It's a pleasure to hear it crank over vigorously even from a cold start and having sat for a few weeks.

Hope this post helps anyone else who needs to replace their starter.

[Busskipper]

Originally Posted by Mike D

My 2005 T-S Select wouldn't crank over. After I determined that the starter was the problem I decided to replace the original starter with a Denso gear reduction starter.

The engine is a Cummins 500 HP.

The O.E.M.starter was labeled in it's ID tag as a Cummins part # 3103304. There was also a Delco part number on the tag (8200694). It was a Delco MT39 starter and had never cranked over all that great,especially after sitting for some time.

The Denso web site's cross reference showed no Denso equivalent to either the Delco or the Cummins parts numbers. I spent some time on IRV2 researching what others have done and determined that the Denso TG428000 4430 was the best shot.

I bought a new Denso starter (TG428000 4430) but when put side by side I found that the Denso starter had a 10 tooth drive gear vs the Delco's 11 tooth drive gear. Both starters had the same pitch gear teeth (6/8 pitch) but the Denso was noticeably smaller.

I made some careful measurements of both starters and found that the Denso's drive gear was offset closer to the engine vs the Delco's drive gear. I was able to determine that the Denso would engage the flywheel as fully as the Delco starter drive gear.

Other than that issue the starter looked like a good fit. As installed the Denso's solenoid was on top of the starter, same as the Delco/Cummins starter and the drain vents on the Denso pointed towards the ground as they should.

I went to the Delco Remy web site cross reference and found that the Denso starter crossed to the same replacement part number as the Cummins and Delco part numbers crossed to.

I installed the Denso and it works perfectly. It's a pleasure to hear it crank over vigorously even from a cold start and having sat for a few weeks.

Hope this post helps anyone else who needs to replace their starter.

Good Job,

[The Driver]

Thanks for the clue!

[Any ole Joe]

Mike D, thank you for posting this! I have an 07 Essex, ISM 500 with a Delco starter PN 3103951. I could not find a cross reference, but also decided to try Denso 428000-4430. I removed the old starter, installed the new one and it does not crank. It clicked on the first try, nothing since then. New batteries, the Voltage on the starter positive and negative post is the same as the battery, so I have a solid connection. The voltage on the starter control circuit to the solenoid was all over the place, bounced from 19v down to 5v? When engaging the ignition switch, there is no drop in voltage. The Delco has a control relay on top of the solenoid (see pic). Any chance I need this relay on the new starter?

As always, what appears to be a straight forward... never is [emoji41]. Any assistance from starter savvy IRV2 folks would be greatly appreciated.

[twinboat]

Originally Posted by Any ole Joe

Mike D, thank you for posting this! I have an 07 Essex, ISM 500 with a Delco starter PN 3103951. I could not find a cross reference, but also decided to try Denso 428000-4430. I removed the old starter, installed the new one and it does not crank. It clicked on the first try, nothing since then. New batteries, the Voltage on the starter positive and negative post is the same as the battery, so I have a solid connection. The voltage on the starter control circuit to the solenoid was all over the place, bounced from 19v down to 5v? When engaging the ignition switch, there is no drop in voltage. The Delco has a control relay on top of the solenoid (see pic). Any chance I need this relay on the new starter?

As always, what appears to be a straight forward... never is [emoji41]Attachment 303245. Any assistance from starter savvy IRV2 folks would be greatly appreciated.

Yes you need thst or a seperate relay close by.
Otherwise your trying to engage the large solenoid with about 40 feet of wire from the front.

[Any ole Joe]

Thanks! I’ll give it a try...

[Any ole Joe]

Well, the Delco starter relay did not solve the problem... still turn the key and nothing? Any other thoughts anyone?

[twinboat]

You may have blown a fuse, without the relay in the system.

Check the signal wire from the front, when the key is turned to start. Should see 12 volts.

Does the starter motor have a ground cable connection ?

If it does, that may need a cable to the chassis. Found that with a aftermarket starter on my diesel boat engine.

[Any ole Joe]

Thanks twinboat! I’ll check both in the morning...

[Any ole Joe]

Well, I have checked all fuses and relays that I can find... all good. The starter is grounded to the chassis. The good news is I can now jump start from the starter to the control relay posts that goes to the solenoid. Think I have it isolated to this one wire because it shows 0 volts with the key in the on position (nothing when turned to start). When the key is on, there is voltage at the front of the motorhome in the left front compartment on the ignition posts. Goes off with key off and no drop in Volts when turned to start; however I do here a click. So I have lost 12v power somewhere between the ignition post and the solenoid. Looking for a wiring diagram for an 07 Essex to see what is between the ignition and the solenoid. Thanks again for all the replies. Any other thoughts would be greatly appreciated as I run this wire down.

[Any ole Joe]

Received the wiring diagram from spartan, anyone know where the backbone Bussmann is specifically located on an 07 Essex? I know it is in the rear of the coach. Diagram says that is the location of the starter relay.

[The Driver]

Thinkin you'd get more Newmar eyes on your questions if you'd start a thread on their forum.

I'm following with interest for whatever application it may have for my 06 TS.

[Any ole Joe]

[emoji106]