PG260 Starter Upgrade on the LT1 and L05

N0DIH · #1 (**permalink**) 10-30-07, 02:41 AM

Well, if you have a 93 L05 or a 94 and 95 LT1's you are stuck with the old PG250 starter. The PG250 is a good reliable starter (mine just came off at 235K miles), but they are very difficult to rebuild and parts are not readily available. Don't get into one of these if you aren't very mechanically inclined. And when you read the warning about the strong magnets able to pinch you. LISTEN! It will BITE you!! It got me and I was trying hard not to. If you aren't very careful it will draw blood.

A lower cost (rebuilt to rebuilt from most auto parts stores, here it is $160 for the PG250 and $130 for the PG260M) is to upgrade to the 96-97 LT1 PG260 starter. The PG260 is a even further gear reduction with more power and lighter weight. Less current draw than the SD250/5MT starters. 10MT's will NOT fit an LT1 no matter what you do.... I am not sure if the SD250/5MT will fit. The only "mod" needed is to install shorter bolts. Around 1/2" is needed less, more like 9/16" less is ideal. I just used 2 old lug nuts as spacers with no issues at all. You will LOVE the lightweight of the PG260M. It is almost wrong how right it is....

A little background:
The Small Block Chevy has 2 flywheels and 2 starter noses.
153 tooth and 168 tooth
Offset bolts and non-offset bolts (these are the mounting to the engine bolts)

The LT1's and at least the 93 L05's (likely more) have a 153 tooth flywheel, with non offset mounting bolts. I am betting any 90-92 Chevy powered Cadillac can also use the PG260M. But you need to check.

You CANNOT use the PG260 from the Tahoe/Suburban/Trucks. This one is for the 168 tooth flywheel and the offset mounting bolts.

There are a few starters out there:
5MT/SD250 (direct drive, no gear reduction) old school direct drive, very heavy. ~20 lbs

10MT-direct drive, no gear reduction, this is the old "big block" starter, very very very heavy! ~25 lbs (gotta confirm the pict here on the 10MT)

PG250-Planetary gear reduction, 1.4kW, I believe a 4:1 gear reduction ~10 lbs. Note no visible bolts mounting the solenoid, and NO bolts outside the sides of the motor

PG260M-Planetary gear reduction, 1.7kW, 4.4:1 gear reduction ~7.7 lbs. Easily ID'd by the 2 long outside of the motor bolts.

Corvette Mini Starter (can be used, not discussed here, often expensive, but very light)

So, in summary:
As long as you keep the right flywheel and right mounting bolt offset, you can almost always interchange these starters as long as they physically fit.

Most of this info applies to traditional Buick V8's also (350/455), and most likely the V6's in rear drive configuration. The Olds and Pontiac V8's have starters on the opposite side of the blocks and none of this applies (sorry! I have a Pontiac 400 that I wanna drop on a gear redux starter!) Aftermarket has them, but the costs are pretty steep.

I do believe this is a good starter for the Cadillac 4.5/4.9L V8's. But I think the starter is clocked the wrong way (Olds/Pontiac clocking). I have never been under a Cadillac Big Block (6L/7L/7.7L/8.2L), so I can't say on those.

**jayoldschool** · #2 (**permalink**) 10-30-07, 09:59 AM

I have the Corvette starter on my Impala SS and I am happy with its performance. Sounds cool too!

"I have never been under a Cadillac Big Block (6L/7L/7.7L/8.2L), so I can't say on those."

The starter on these is on the right side, so your listed options may work...

N0DIH · #3 (**permalink**) 10-30-07, 02:15 PM

I can say the PG260 sounds different than the PG250 even. And WAAAY different than the SD250/5MT....

What does the Vette starter sound like? Is it lighter than the PG260M?

caddycruiser · #4 (**permalink**) 10-30-07, 06:20 PM

Quote:

Originally Posted by N0DIH

I can say the PG260 sounds different than the PG250 even. And WAAAY different than the SD250/5MT....

What does the Vette starter sound like? Is it lighter than the PG260M?

If you've ever heard a modern Chrysler vehicle, for one (they use or used Nippo-Densos of the same design), with that slightly chirpy start sound, that's it.

Or, here's an actual video clip of a Roadmaster with the gear reduction Vette starter:

http://videos.streetfire.net/video/5...5b4105d3b1.htm

N0DIH · #5 (**permalink**) 10-30-07, 06:23 PM

Sounds decent. I'll have to record mine one of these days..... Not too far off. Definitely different than the PG250...

JTraik · #6 (**permalink**) 10-31-07, 02:42 AM

Im a fan of the direct drive monsters. They are reliable, cheap, and take about 20 minutes to rebuild for about 20 bucks. I have one in my '68 (10mt) and one in my '93 9C1 (5mt). I have at 10mt sitting on my workbench and someone always asks what its out of and are like "damn thats huge!" Then I tell them to pick it up.

btw: Thats not the right pic for the 10mt

N0DIH · #7 (**permalink**) 10-31-07, 11:28 AM

I'll see if I can find another I wasn't sure. A friend of mine next door has a 10MT for a 153 tooth flywheel. Looks new, for sale also (make any offer, he just doesn't need it, it is for a GM and he drives fords....). It is just too big to fit my 454 (99 K2500 Suburban with the L29 454) and not a chance to fit the LT1.

Try this one....

JTraik · #8 (**permalink**) 10-31-07, 03:39 PM

Yep thats the girl!

N0DIH · #9 (**permalink**) 10-31-07, 04:47 PM

IIRC the 15MT and 25MT are diesel starters and don't work on the regular small blocks. They are the direct drive motor with a non planetary geardrive. They make tremendos amounts of power.

I love the 7.7 lb weight of the PG260. SOOO nice being lightweight. Can you weigh a 10MT and a 5MT? I am curious!

Any place we can lose weight is a good thing. And the slower rpm has sooo much more torque than the direct drives it is well worth it. I agree, the old 5MT/10MT are easy to rebuild, love that part of it. But I have found the power requirements of the PG260's are lower too, they take upwards (so I am told) of 100 amps less power to crank over in cold weather. That is the difference between starting and not on a cold day... And allows for a smaller lighter battery, and smaller thinner lighter battery cables.

JTraik · #10 (**permalink**) 10-31-07, 10:21 PM

The 10mt is 25lbs on the scale... the 5mt is on the Caprice right now! I personally like the weight... the suspension was engineered for it.

At work we had the starter out of our GMC TopKick box truck. Those starters are like a giant 10mt, direct drive monsters. These are another reason I am a fan of these... this particular truck had terrible compression when cold, and in the dead of winter and with the block heater cord ripped off, it was solely up to the starter to get this thing going. We would LITERALLY crank this truck for 5-10 minutes nonstop... it was someones job in the morning to sit in the truck and hold the key. The starter in this truck did this every winter for years and never had a problem.

Less moving parts in these direct drives provide for longer life perhaps??? Do the gear reduction starters uses bearings or bushings? I always slobber the hell out of the bushings with grease or never seize.

N0DIH · #11 (**permalink**) 11-01-07, 01:34 AM

I have never seen a SD starter survive longer than the PG's so far. I have seen much longer life in the PG's. My Cadillac went 236K on the stock PG250. My 91 Cadillac Deville went 170K on the OEM 5MT. Granted, it was a $30 to do a new armature and new brushes (about all you can do to rebuild them, unless something is damaged).