Hi everyone, My Spec aluminium flywheel has just shaken itself loose!! Don't think the bolts have sheared....yet?!
Can I "drop" the Getrag transmission while keeping the cradle and 3800 S2 motor in place? Or do I really have to drop the cradle to have proper access?
Should I use another aluminium flywheel or revert back to cast iron flywheel (or maybe a custom steel flywheel)?
What torque setting should I use to put a new flywheel in place? So this doesn't happen again! (I had used ARP bolts and 35ft/lbs torque setting.)
All and any input would be greatly appreciated, especialy from anyone who has had trouble with aluminium flywheels.
Should I use another aluminium flywheel or revert back to cast iron flywheel (or maybe a custom steel flywheel)?
What torque setting should I use to put a new flywheel in place? So this doesn't happen again! (I had used ARP bolts and 35ft/lbs torque setting.)
All and any input would be greatly appreciated, especialy from anyone who has had trouble with aluminium flywheels.
You're supposed to be asking these questions before you stick an aluminum flywheel on your engine.
There have been a lot of posts here about "aluminum creep" over the years. I think you'll find some helpful info in This thread.
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Originally stated by fieroguru:
Aluminum creep is often caused by the hole being too large, the bolt head being too small, and the material thickness being too thin at the bolted attachment. This causes very high localized pressure and room for the material to "flow" into.
If you wanted to run a Fidanza flywheel and address the creep issue, just press some thin steel bushings into the existing holes and leave them about .030" shorter than the thickness of the flywheel. The issue is the bolt holes are way too big, which reduces the area of the material the clamp force is spread against and makes it easier to "flow". The sleeves don't reduce the pressure, but they support the material and eliminate the opening it has to flow into, which will greatly reduce the chance for it to work loose.
[This message has been edited by Patrick (edited 03-26-2015).]
I have done it several times, and dropping the entire cradle is easier for me. It also gives you a chance to replace any other problems, main seal for example, or waterpump etc,
I have removed and replaced exactly one tranny while leaving the engine in the car. As far as I'm concerned, the only advantage is that you don't have to mess with the wiring, fuel lines, and coolant lines. Otherwise, it's every bit as much trouble.
I used an A-frame, with a chain hoist to support the engine, and a come-a-long to lower and raise the trans.
I've had real good luck with using blue loc-tite on the bolts.
The common problem with aluminum flywheels is not that the mounting bolts are backing off and getting loose, it's that the aluminum of the flywheel is getting mooshed (that's my technical term ) where the bolts go through the mounting holes. That's what the "aluminum creep" is. The end result is that the mounting bolts are no longer securing the flywheel tightly to the crankshaft.
If it's just a clutch issue, I just drop the cradle/transmission and support the engine. The time to remove is about the same, but the reinstall time is much shorter as you don't mess with the wiring, fuel, coolant, and brake fluid. On swapped cars, it really depends on how you routed everything.
I would just drop the whole cradle. You can do it in a day if you have never done it before. Last time I did it in about 6 hours. Organized tools help.
Thanks everyone for the good advice. I'll probably drop the whole cradle - gives me more space to work. It's just a pain to have to disconnect everything: Brakes, fluid lines, intercooler, wireing etc...
I'll see what can be done for the alu flywheel.... ....maybe inserts in the bolt holes, and loads of locktite !
Regards, Rafe
[This message has been edited by Englishrafe (edited 03-29-2015).]
you dont have to disconnect the brake lines, Just disconnect the e-brake system and remove the calipers. U don't have to drain the oil either. just the coolant.
Here is some material that might help if you get stuck.
Yeah, thanks for the links! I'll be taking out the entire cradle next week. (I had just hoped that there may have been some shortcut so as not to totally unplug or undo everything.)
For the aluminium flywheel, has anyone got a photo of the little inserts that could be used to take up the space between the bolts and the holes? I read that someone had cut short lengths of brake pipe? I wonder if they should be ever so slighty smaller than the depth of the hole? To allow the bolt to torque down?
As well, I'm rather afraid to find that the flywheel is "shot"? Holes too far worn by the few minutes driving before I really realised that there was this problem and shut down the engine!
Once I've dismanteled everything, I'll post up a picture of the flywheel.
For the aluminium flywheel, has anyone got a photo of the little inserts that could be used to take up the space between the bolts and the holes? I read that someone had cut short lengths of brake pipe? I wonder if they should be ever so slighty smaller than the depth of the hole? To allow the bolt to torque down?
Seems to me that's what fieroguru was suggesting (as posted previously).
quote
Originally stated by fieroguru:
...address the creep issue, just press some thin steel bushings into the existing holes and leave them about .030" shorter than the thickness of the flywheel.
Anyway, I'd just like to add that I've had a Fidanza aluminum flywheel in my Fiero for almost 10 years, and it's never come loose. Maybe the Spec flywheels are made of a softer alloy, or something?
Edit to add: my flywheel bolts are torqued to 40 ft-lb, if that makes a difference.
[This message has been edited by Blacktree (edited 07-18-2016).]
