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Are SkyTec starter pinions replaceable?
- Thread starter tass
- Start date
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When SkyTec starters started in business, they did repair their starters. Now that they have been sold and are a part of Hartzell Engine Technologies, I would suggest contacting them and see if they can repair your starter.
While I have disassembled an NL starter to replace the solenoid, I did not disassemble the forward portion with the pinion gear. However, I am sure it is quite simple to do so. Unfortunately, skytec does not sell replacement parts. The electrical guts were denso COTS components, so expect the pinion is the same. However, unsure if the gear pitch used for lyc flywheels if found out there in the auto world. Likely difficult to find. SUggest taking it to a starter shop and see if they have components to match. That is where I sourced the denso solenoid parts and the shop was surprisingly familiar with Skytec. I am pretty confident that the only thing actually engineered by skytec was the case. The rest is all denso, who IIRC is the worlds largest maker of these. If you look closely at the starter, it closely resembles the style used by Toyota.
Larry
Larry
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Thanks for the responses!
I'm not holding out much hope for finding the parts, but did find a couple of shops that seem to specialize in starter and alternator rebuilds which I'll give a call along with Hartzell on Tuesday.
One more question - is it possible to tell by sight which kind of pinion is installed? My starter was mismatched to the ring gear (starter 149 tooth, ring gear was 122). I just replaced the flywheel + ring gear but I'm slightly suspicious that the pinion in the starter was replaced with a 122-matching pinion - I don't know how to tell for sure, but I never had problems starting besides it sounding a little off. If I get the pinion replaced I want to be sure they put in the right one for a 144 tooth ring.
Maybe having a broken tooth is evidence enough that they were mismatched?
I'm not holding out much hope for finding the parts, but did find a couple of shops that seem to specialize in starter and alternator rebuilds which I'll give a call along with Hartzell on Tuesday.
One more question - is it possible to tell by sight which kind of pinion is installed? My starter was mismatched to the ring gear (starter 149 tooth, ring gear was 122). I just replaced the flywheel + ring gear but I'm slightly suspicious that the pinion in the starter was replaced with a 122-matching pinion - I don't know how to tell for sure, but I never had problems starting besides it sounding a little off. If I get the pinion replaced I want to be sure they put in the right one for a 144 tooth ring.
Maybe having a broken tooth is evidence enough that they were mismatched?
the 122 and 149 ring gears require different pinion gears. They have different tooth counts and/or a different pitch IIRC, but don't remember the numbers. A msimatch here is likely to create broken teeth. Pinions are hardened and the ring gear is not, so would expect the ring gear teeth to break first.
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Thank you, in my case the actual starter pinion has a broken tooth and the ring gear was fine. I'll see if Hartzell will answer how many teeth a 122 pinion vs 149 has before I contact a rebuild shop.
Basically I'm a little surprised that I went for over 2 years not knowing it was mismatched (and however long the old owner ran this way), which is why I suspect the pinion might have been switched even though the starter model says it's a 149 - I would have expected a label or something pointing this out though. On the other hand, the 122 teeth are bigger so this might be enough to put the hardened starter teeth at a disadvantage.
I confirmed with Hartzell that there are no repair procedures or part numbers available - this isn’t officially a repairable product. However a 149 model has 10 teeth on the pinion gear, and a 122 model has 9 for anyone wondering.
Time to find a shop willing to dig through their parts bin.
Time to find a shop willing to dig through their parts bin.
Got a new starter pinion installed, along with a replacement solenoid since the old one didn't test to be reliable.
The mechanic told me it's the same pinion as a 90s Ford Taurus: part 4-355, which possibly means something to someone, but I can't find anything concrete.
He also pointed out it was wired incorrectly, though it seems to line up with what I can find in the Skytec docs, so I'd love to hear other opinions.
He said, being a permanent magnet starter, it should have 2 wires: One (large gauge) always energized, and a second wire separately attached to the smaller post on the starter with #10 wire which is engaged by the starter relay.
He demonstrated it on the bench: When wired up the way I had it (with both power terminals linked together), removing power kept the pinion engaged for a few more seconds as the starter spun down. When wired up the way he suggested, removing power only from the trigger terminal immediately retracted the starter pinion (i.e., what's supposed to happen).
Looking at the Skytec instructions, it only mentions a single power terminal, and though it's hard to see in the diagram I believe the two power terminals on the solenoid are joined together.
Can anyone confirm that Skytec XLT starters are typically wired with only 1 wire? Is there a reason I shouldn't run a second wire besides the effort in doing so?
Here's a similar guide to doing this in a car though the timing of the pinion retracting isn't mentioned.
Edit: I just found this specifically mentioning the delay in disengaging.
The mechanic told me it's the same pinion as a 90s Ford Taurus: part 4-355, which possibly means something to someone, but I can't find anything concrete.
He also pointed out it was wired incorrectly, though it seems to line up with what I can find in the Skytec docs, so I'd love to hear other opinions.
He said, being a permanent magnet starter, it should have 2 wires: One (large gauge) always energized, and a second wire separately attached to the smaller post on the starter with #10 wire which is engaged by the starter relay.
He demonstrated it on the bench: When wired up the way I had it (with both power terminals linked together), removing power kept the pinion engaged for a few more seconds as the starter spun down. When wired up the way he suggested, removing power only from the trigger terminal immediately retracted the starter pinion (i.e., what's supposed to happen).
Looking at the Skytec instructions, it only mentions a single power terminal, and though it's hard to see in the diagram I believe the two power terminals on the solenoid are joined together.
Can anyone confirm that Skytec XLT starters are typically wired with only 1 wire? Is there a reason I shouldn't run a second wire besides the effort in doing so?
Here's a similar guide to doing this in a car though the timing of the pinion retracting isn't mentioned.
Edit: I just found this specifically mentioning the delay in disengaging.
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Majorpayne317641
Well Known Member
I can hear my sky tech drag for a couple of seconds before it disengages. If this is true then it all makes sense as to why this happens on mine. I don’t like it but it has been running like this for 1000 hours without issues.
Off the plane and on the bench, it’s very obvious - I’ll see if I can duplicate it at home and grab a video before I mount it.
Ha scratch that, I definitely need a more capable power supply than I just tried that with.
Out of the box it is wired as a one wire engagement. The second post is ONLY for selecting 12/24V.
skytech used a special coil that is designed to accommodate 12 AND 24 volts, by having a fourth winding lead. Now that you have moved to a more standard three lead coil, there is no reason to bridge them, as sky tech did. I took the two coil leads out to the small post and kept the exterior bridge wire, but could easily remove that to provide a separate source. Howwever, this was NOT how it was wired when I took it apart.
The thick lead is the pull winding and the thin lead is the hold winding. Not sure your guy explained it correctly. The way that the starter is wired, any power to the large lug will engage the solenoid and it will start spinning. It can be rewired a different way, as I did, but you need to confirm how your guy wired in the coil leads. It can be a bit confusing as they use polarity to engage the pull vs hold windings without using a relay. You want the pull winding out of the circuit once the contactor lugs MAKE. They do this by having the pull winding grounded to the commutator instead of the case, thereby stopping current flow once the lugs make contact. The hold winding is always grounded via the case.
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My explanation was more my interpretation of the repairman’s explanation more than anything, so any error is much more likely my fault.
On the old solenoid (now replaced) there were 3 terminals. One going to the motor (with a thick cable), one other large terminal (battery terminal?), and a small terminal (start terminal?). The battery and start terminals were tied together. The new solenoid is the same but without the tie. Maybe the existing solenoid was non-original?
As I now understand it, the start terminal powers the pull coil (wired between start and battery - with a diode?) and the hold coil (wired between start and ground). Without power to this terminal, the solenoid disengages and the starter motor stops and disengages.
Here is where my understanding of electrical engineering falls flat and my completely dodgy explanation follows. If power is pulled from both the start and battery terminal at the same time, I’m assuming it’s the pull coil that somehow gets energized by the permanent magnet acting as a generator. If the battery terminal remains connected, this doesn’t occur because of the 12v remaining on the other side of the pull coil (because with the battery side at 12v, this generator can’t create enough potential??).
Anyway, in the bench test it was obvious that tying them together kept the pinion engaged for longer than power was applied.
On the old solenoid (now replaced) there were 3 terminals. One going to the motor (with a thick cable), one other large terminal (battery terminal?), and a small terminal (start terminal?). The battery and start terminals were tied together. The new solenoid is the same but without the tie. Maybe the existing solenoid was non-original?
As I now understand it, the start terminal powers the pull coil (wired between start and battery - with a diode?) and the hold coil (wired between start and ground). Without power to this terminal, the solenoid disengages and the starter motor stops and disengages.
Here is where my understanding of electrical engineering falls flat and my completely dodgy explanation follows. If power is pulled from both the start and battery terminal at the same time, I’m assuming it’s the pull coil that somehow gets energized by the permanent magnet acting as a generator. If the battery terminal remains connected, this doesn’t occur because of the 12v remaining on the other side of the pull coil (because with the battery side at 12v, this generator can’t create enough potential??).
Anyway, in the bench test it was obvious that tying them together kept the pinion engaged for longer than power was applied.
