speedshifter

iTrader: (1)

Hey guys,

I'm doing my 2nd of many LS swapped Mustangs, but my first with a manual trans. I'm trying to install the trans to the engine, but i'm stuck with about a 1/2" gap between the motor and bellhousing and it can't go any further.

Here are the parts I'm using:

6.0 truck motor
T-56 Magnum TUET11009
2009 Pontiac G8 GXP bellhousing #89059423 (measures 5.767" thick)
LS7 Clutch #24255748
LS2/3/7 Flywheel #12571611
Slave Cylinder 2009 G8 GXP #92227219
Pilot Bearing #12557583

Now upon finding this problem, I google'd it and searched on the forum to find that I was using the new style pilot bearing and that this problem has been fixed with using the old style pilot bearing #14061685. My preliminary measurements confirmed the pilot bearing was sitting out too far, so I switched to the old style bearing.

2nd try, went to install the trans, still the same problem. Now I removed the clutch and just tried installing the trans with the flywheel only, it fits. I took tons of measurements with a vernier caliper and a straight edge. Come to find out that the slave cylinder sleeve is hitting the clutch disc hub. According to my measurements and calculations, this is leaving my with a 0.400" gap between the bellhousing and the block.

Anybody see this before?

I know the LS7 clutch can't be the culprit. That leaves me with the flywheel, the slave cylinder, or the bellhousing. From what I've read here, most of the LS bellhousings are 5.5" deep. This one is measuring just over 5 3/4", so I should be fine there. I'm left with either the flywheel sits out too far off the block, or I'm using the wrong slave cylinder. I already bought and installed the McLeod hydraulic clutch conversion system for Mustangs and got the one with the adapter for 2005+ quick disconnect style slave cylinders.

Any help would be appreciated!

jmd

iTrader: (4)

Good job for putting some PNs, research, and dimensions out there with your question.

My take:
Your GXP bell is about .270" deeper than the 98-02 F-body / 04-06 GTO bell
Your "tall" / "later model" GXP slave is more than > .270" taller than the "short" slave used in the above mentioned models.

Parts store should have a "short" 97-04 Vette, GTO, or 98-02 F slave for quick and easy measurements to verify (the lines vary; the slave itself is dimensionally the same across those.)

Yeah, a .400" longer truck crank could give you a similar problem. But it's noticeable that the rear flange sticks out (You'd know; the short / car crank is relatively flush with the seal.) Or the extended starter pinion wouldn't line up with the flywheel teeth.

The GXP parts are a real animal when trying to mix them; many year to year changes. But I guess you knew that.

With this build, go back and re-verify pilot engagement (should be excellent with the Magnum input,) spline engagement and slave shim before moving forward.

speedshifter

iTrader: (1)

So you are saying the truck crankshafts are .400" longer? I did not know this. I have not mocked up the starter yet, but there is a significant amount of space between the back of the flywheel and the block.

Moving forward, I won't use the GXP parts on future builds. I chose them because the GXP is the newest car I could find that used a separate bellhousing (Camaro's is integral). Newer model = better availability and usually lower pricing through GM. Cars that are under warranty tend to have cheaper parts pricing from what I have found.

If the crank is longer, what can I do to make this work?

If not, I just go with the shorter style slave? Are there any '05+ slaves that are short? McLeod specifically said my kit was for '05+ slaves and comes with the quick connect adapter for them.

speedshifter

iTrader: (1)

Okay, the truck 6.0 (LFA) crankshaft is the same #12588612 as 05-13 Corvette and pretty much anything else that has ever used a 6.0 or 6.2. Therefore, crankshaft cannot be longer.

SNLPerformance

iTrader: (15)

Crank shouldn't be an issue with that new 6.0, need to get this measurement (https://ls1tech.com/forums/manual-tr...need-shim.html) to determine what size custom adapter shim you need for a 4th gen or C5 slave as that's what we've done in the past with conversions and you can sell your expensive GXP slave/return Mcleod quick disconnect conversion piece. Hope that helps and look forward to you running a Monster next time

speedshifter

iTrader: (1)

I've already been in touch with Billy @ McLeod and he said he would exchange out my AN hose and 05+ slave cylinder line adapter fitting for the assembled AN quick connect line for a 4th gen slave if I needed to.

I'll go though the measurement process when I get home and update what I find.

I got a sweet deal on the LS7 clutch for this build, but when I do my own car, I'm going to need something better. I'll be doing a Procharged 6.0L in my '95 Mustang with a Viper TR-6060 behind it. I'll contact you about a Monster when the time comes. Thanks.

speedshifter

iTrader: (1)

In regards to the flywheel, I assume that the corvette flywheel # I posted is correct for a LS7 clutch application then? It sounds like the main concern is probably the slave cylinder, but I will mock up a starter just to be sure the flywheel lines up ok.

SNLPerformance

iTrader: (15)

Understandable, good deal.

That's correct, sounds like a plan.