5 speed questions

[sbnova]

I've been searching and come up with plenty of 4l60e answers, but virtually nothing for 5 speeds.

I know there are a few different m5's used in these trucks. I have a 1988, and I need to replace the clutch and the trans input seal. Will any Chevy 12" clutch work? I've always liked Exedy, but there's also a Luk cerametallic puck type that I see listed. Has anyone used it?

And most importantly- how do I remove the shifter? The rest of the trans removal is simple.

Thank you

 

[5speed91]

Assuming you have a 5.7L. The 4.3L and 5.0L use an 11 inch, the 5.7L uses the 12 inch.

To remove the shifter, turn the handle counter clockwise and unscrew it. Then pull back the rubber boot enough to access the screws beneath it. Remove the screws to get the boot off. Then there are 4 bolts that attach the shifter assembly to the transmission. A lot easier than it sounds.

 

[sbnova]

Well I guess I'm stuck until I take it apart. The truck was originally a 5.0 and a 5.7 was put in by the previous owner so I'm really not sure. I guess I'll have to measure before I buy a new one.

Does anyone have any recommendations for a clutch? My 5.7 is 100% stock besides the exhaust and it may never get more than a mild cam installed.

 

[sbnova]

Oh and thank you for the shifter removal instructions!

 

[5speed91]

Well hopefully who ever installed the 5.7 installed the bigger clutch lol. Most would assume the v6 has the smaller clutch and the 2 V8s are the same but after doing the research and actually doing the same thing myself I can def say the 4.3 and 5.0 motors have the 11 inch diameter and the 5.7 uses the 12 inch dia. I recently pulled out my tired old LO3 305 and installed a L31 vortec 5.7 in its place. I just used a stock for my year model clutch made by LUK and also a LUK 5.7L flywheel. You will need the larger diameter flywheel to match the clutch as again, the 4.3L and 5.0L come with the smaller clutch and matching smaller flywheel

 

[5speed91]

Based on the fact that all 4.3 5.0 and 5.7 engines are based on the same engine family (SBC Gen I) I believe that in reality you "can" install the smaller clutch into a 5.7 or install the larger clutch in the 4.3 or 5.0 but the way I see it installing the smaller clutch in the 5.7 is asking for trouble especially if you are 4WD or have a larger cab configuration, or larger tires. I believe (but don't know for a fact) the only reason the smaller 11 inch diameter clutch and flywheel are used in the 4.3 and 5.0 engines is reduction in rotating mass on the engine to reduce power loss of the smaller less power engines that may not quite need the clamping force of the larger 12 inch clutch and flywheel. Hope that makes sense the way I wrote it. When you order your replacement, just go ahead and do it the right way and order a new clutch, matching size flywheel, new pilot bearing and new throw out bearing. That way there are no surprises and it wont really matter what size came out of the truck, all of your new parts will be matching, compatible and will be right for your 5.7 application. order all parts for your make model of truck but with the 5.7L

The only reason you need to wait and measure your current parts is if you want to re-use the flywheel in which case you need to make sure it already has the 12 inch one. But if it were me, I would just order a new flywheel with the new clutch.

 

[sbnova]

Actually I was planning to buy a new flywheel too, so it makes sense that if I just buy everything that it will all work together no matter what it's replacing. Thanks!

Do I need to know exactly what 5-speed I have to get a new front seal for it? Or do all the possible variants use the same seal?

 

[CrustyJunker]

Actually I was planning to buy a new flywheel too, so it makes sense that if I just buy everything that it will all work together no matter what it's replacing. Thanks!

Do I need to know exactly what 5-speed I have to get a new front seal for it? Or do all the possible variants use the same seal?

I've changed this front seal on mine (still leaks), but I was able to get mine ordered through a dealer. If I'm not mistaken, input shaft diameter should be the same.

 

[5speed91]

There are many variants of the transmission but if your truck has the original transmission then as long as you order for a 1988 model there should be no problems with you getting the right part.