Here is the pics of the damage. It looks like there was a lot of stress on the tranny mount and cracked part of the cradle. That cradle is cracked in that one spot but it can be fixed. The poly mounts look like the culprit but I dont know for sure. I think its a combination of a spec clutch, poly mounts, and a stiff suspension. What do you guys think if I ran stock rubber mounts and put another Getrag behind this setup? It bent the hell out of that Tranny mount in the pics. Tell me your diagnosis people. Thanks. Anyone else running poly mounts with the Getrag? I have a chance at another Getrag possibly but I dont know for sure if it is even worth the hassle.
-Amir
------------------
Maroon 1987 GT 5 spd: 2.8L Ferrari Red 1988 Formula 5 spd: 3800 Series II Supercharged In & Running.....
------------------ Ferrari 308 GTB rebody on a modified 86SE chasis Soon to have a highly hooped up 3800SC..Ohh yeah baby!! Contacts _ AIM / Zildjianfx _ Yahoo / djdraggin Remember, always brush your milk, drink your teeth, dont do sleep and get eight hours of drugs.
In my opinion, judging by the way the casing is damaged: 1) Internally something cut loose (gear,shaft) which in turn caused A) The trans to lock up {complete stop} which was followed with a shattering of the casing. B) The trans coming to a complete stop caused the damage to the mounts/cradle.
Just my 2 cents and 30+ years of experiance........ Take it as you see fit!
PS That was either some very wicked NOS or you hit a dry spot during a wet burnout, or maybe you just got a lotta balls in your 3800SC!
[This message has been edited by FieroHarry (edited 04-19-2004).]
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10:21 PM
Rare87GT Member
Posts: 5068 From: Wichita, KS USA Registered: Oct 2001
Yeah I dunno. Im just wondering how that tranny mount decided to get bent and stuff. What in the world would do that. I thought the poly mounts were suppose to be strong as hell.
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10:39 PM
FieroHarry Member
Posts: 1809 From: Virginia Beach VA Registered: Apr 2001
Yeah I dunno. Im just wondering how that tranny mount decided to get bent and stuff. What in the world would do that. I thought the poly mounts were suppose to be strong as hell.
When it went out on you did it lock up the tires? If so the stopping of the rotating mass (All at once)did the damage!
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10:43 PM
Formula88 Member
Posts: 53788 From: Raleigh NC Registered: Jan 2001
I tend to agree with FieroHarry about something breaking up inside and jamming the tranny,it had to be under some serious stress for it to bend the mount which cracked the case. Dissemble the tranny and look at the internals before trying to switch to an automatic.
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11:07 PM
fierodustin_86 Member
Posts: 970 From: Joplin, Missouri Registered: Aug 2002
From the photos posted, it would appear to me that the failure was caused by severe stresses externally to the case (not internal), in other words the trans was moving more that the engine due to how both were mounted. Does that crack in the cradle appear fresh, doesn't appear so in the photo. Hard to tell from just a coupe photos, but this appears to be external forces at work. Be careful how you observe that failure, with that much case damage, no doubt it caused internal damage when parts weren't aligned right. Just my opinion.
polly mounts everywhere on the car, and I've been driving it a bit crazy the past 2 days. Checking to see if my problems gone and it appears to be, injector cleaner works wonders.. think the gas stabalizer screwed with me.
I'm a bit leary of rubber from the torque and hp the motor puts out, that'll flex a lot more then polly ever dreamed of. Quick example when I pulled the 3.4 out the motor moved quite a bit, dad and I stuck the new motor on there with polly it wouldn't even budge. I believe it does a tiny bit that its broken in.
I'd say go with what you feel comfortable with, tough call I sure as heck wouldn't even know which route to go. I love the 5spd it shifts unbelievably smooth in every gear for me and people have told me thats odd for a fiero. Go with what your gut tells you, look all the stuff over see if you can figure out what happend.. if not hit up the auto and try that.
ok I'll shut up now its really late for me and I need sleep so I'll quit rambling on
Amir, what I said in the other post(tech) might help ya out! I am running the poly WCF in the front and rubber on the other three mounts. That engine don't move!
Burn outs? Man, I never do that when racing I might tear up the tranny or clutch. Did I say my car is faster than yours? haha Just get the other 5-sp and slap it in ! (Don't let ryan help ya or drive it again!!!! )
From the photos posted, it would appear to me that the failure was caused by severe stresses externally to the case (not internal), in other words the trans was moving more that the engine due to how both were mounted. Does that crack in the cradle appear fresh, doesn't appear so in the photo. Hard to tell from just a coupe photos, but this appears to be external forces at work. Be careful how you observe that failure, with that much case damage, no doubt it caused internal damage when parts were aligned right. Just my opinion.
That's what I tend to think. If there wasn't a good enough torque strut, the drive train could have twisted, causing the case the crack. Or if some mounts were more solid than others, or even the cracking of the cradle could have been the cause, not an effect.
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09:08 AM
Formula88 Member
Posts: 53788 From: Raleigh NC Registered: Jan 2001
But all in all my set up is in there "solid-ly" mounted by 5 mounts as opposed to just the 4 points of contact. so I should have the cradle crack first I would hope.
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09:19 AM
Fiero STS Member
Posts: 2045 From: Wyoming, MN. usa Registered: Nov 2001
1) That is a VERY common place for an '88 cradle to crack, I've seen several like that, one with the whole mount area ripped completely out. Torque monster that did that? Stock 2.5L.
2) The "poly is hard on stuff" theory doesn't seem to pan out in the real world. From what I've seen, it's the "play" you get with rubber (gives some 'til it loads up, then hits hard...like a slide hammer...) that seems to do more damage than solid mounting. Most of the cracked cradles, broken brackets, etc. were accompanied by some worn out mounts.
3) The front mount/cradle damage was very obviously NOT caused by the tranny locking up while driving...unless he was backing up REAL fast.
Party on---
------------------ Jeremy B.
quote
Our experiences and our opinions differ. No problem; we can agree to disagree. However, please don't take the position that anyone who disagrees with you is an idiot. ---MrPBody
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09:40 AM
GTFiero1 Member
Posts: 6508 From: Camden County NJ Registered: Sep 2001
i say thrown in another getrag and see were you can possibly mock up and add more mounts to the engine. Do you have a torque strut up top? if you dont, add one, it will help greatly. looks like the engine was able to twist while the tranny held solid in place, something had to give on the tranny side and looks like it was the casing that chose to give
------------------ Carbed 2.9 engine build in progress. forged pistons, crane cam, fully balanced, ARP bolts, double roller timing chain and more --Adam-- IM AOL: FieroGT5speed
I have had the same thing happen twice. The differential grenades and the case cracks, this only happens when you have good traction. The last getrag was beefed up and had a phantom differential; it also cracked the case. You need a 4t60 or 4t80 with an aftermarket computer to handle V8 torque. I suggest using solid mounts all around and a torque strut.
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10:18 AM
Black-Azz-GT Member
Posts: 2326 From: Florida Keys Registered: Oct 2003
Also, I dont think it was metioned. Just because a tranny was rebuilt doesnt mean it's stronger. Alot of times once a tranny has been opened and dissasembled, it doesnt always go back together as strong as stock. I used to have tranny problems in my mustang due to the amount of power that was added. I went through six T5's. The best one I had was a low mile, bone stock that hadnt been opened. My experience is stock, unmolested is usualy best. Although I agree it looks more like a mounting/twisting issue, but you'll know better when you open it up.
I would say get a low mile unmolested getrag and install it making sure everything is okay. LTI88GT is running his LT1 with his stock Getrag with 175k miles on it. He has had 15k trouble free miles sence the swap. He also admits to beeting up on it some. This is at least a 300hp corvette engine.
I drove it and it was solid. Do what makes you feel best, but I agree that your car needs the 5 speed. It just fits it. Good luck!
You might want to consider replacing the poly mounts with solids. I think anything over 230 ft-lbs should either be solid-mounted or should use the mounts from the swap vehicle if possible. LS1Swap used the LS1 rubber mounts successfully in his car.
My car also has a SPEC stage III with a Getrag and has quite a bit more power than yours, and there is no evidence of cradle, mount or transmission case problems in nearly two years, and it is solid mounted.
I believe that the poly mounts were at fault in this case. I am not dogging the Getrag at all. I believe it is every bit as strong as it should be. In this case it looks like a failure of too much movement and in relation to the cradle and the poly mount twisted itself in a big jolt at the line at the track. So instead of poly or rubber I should go ahead and solid mount everything with the auto. The auto tranny will take some of the load off the cradle and mounts, but in return will just be a better track car as I am wanting something that is a little easier to drive. I loved the 5spd but hey I guess I found out the hard way of something not setup right.
-Amir
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12:17 PM
KissMySSFiero Member
Posts: 5544 From: Tarpon Springs, FL USA Registered: Nov 2000
Either that or try some stronger mounts. the ones fromt he above post would be nice because he used stronger brackets instead of the stock ones like your using. personally, I'll be solid mounting my V8. At 400lb-fts, I dont want anything moving. Except the car of course.
I've seen damage like that before, Usually it's differential failure, the spider gears will usually shatter long before the case gives out, and in many cases, burnouts and excessive tire spin will cause the differential pin to erode and eventually fail. Either case it will blow the transmission wide open. I have a picture of a Honda transmission that exploded in that manner. I will post a picture of it when I get home from work
interesting i mean i've ripped the metal trans mount bracket in half a couple times and had to reinforce it with 1/8" steel throughout but never have damaged the cradle
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03:48 PM
California Kid Member
Posts: 9541 From: Metro Detroit Area, Michigan Registered: Jul 2001
I've seen damage like that before, Usually it's differential failure, the spider gears will usually shatter long before the case gives out, and in many cases, burnouts and excessive tire spin will cause the differential pin to erode and eventually fail. Either case it will blow the transmission wide open. I have a picture of a Honda transmission that exploded in that manner. I will post a picture of it when I get home from work
I certainly wouldn't disagree with you if the trans had a fair amount of miles on it, but he claims the trans was rebuilt 17,000 miles ago. Any part wear or possible wear flaw should have been detected when the trans was torn down for rebuild.
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05:05 PM
Rare87GT Member
Posts: 5068 From: Wichita, KS USA Registered: Oct 2001
I certainly wouldn't disagree with you if the trans had a fair amount of miles on it, but he claims the trans was rebuilt 17,000 miles ago. Any part wear or possible wear flaw should have been detected when the trans was torn down for rebuild.
Tom it was rebuilt 17,000, but to what extent I have no idea. I am assuming just the normal stuff that would be replaced in a transmission (flywheel, clutch, t/o bearing). I really doubt that the tranny was gone through so I have no idea. The tranny had 120,000 miles on it when I bought the car so I would assume that the differential bearings and everything else inside had the same amount of miles on it. When we put the Spec Stage III in it and new flywheel and t/o bearing nothing else was replaced at this point. This would add to the reason it failed, but I still think the mounts had a big deal to do with it. I plan on adding another mount on the engine side.
[This message has been edited by Rare87GT (edited 04-20-2004).]
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05:43 PM
StansGT Member
Posts: 914 From: Schoolcraft MI, USA Registered: Jul 2001
Geeezzz... I've been running solid mounts on mine for almost 2 years, with much luck, as of 2 minutes ago anyway... "knock on wood" Looks to me that you might have external mounting issues, perhaps there was alot of torsional torque on the case..
Either that or try some stronger mounts. the ones fromt he above post would be nice because he used stronger brackets instead of the stock ones like your using. personally, I'll be solid mounting my V8. At 400lb-fts, I dont want anything moving. Except the car of course.
Thanks for noticing the mounts and sharing the kind words.
Unfortunately, Amir has shared the best pictures of why the stock transaxle brackets are not really strong enough for the additional torque of an engine conversion.
It looks as if the cradle cracked allowing the mount to move side to side enough between shifts and extreme power to ground transfer on your run down the strip to crack the housing. The force and weight transfer of the motor/trans is 100% intended to go straight into the mount/bushing/cradle. It looks as if the trans shifted enough, after the cradle cracked, and the trans housing took more of the force and weight transfer directly on that side of the housing.
I'd say 100% the cradle is at fault here, and Bill's stiffiner is a great option to further strengthen that poorly designed weak spot on the cradle.
Good luck with your fix let us know what happens!
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09:07 PM
Master Tuner Akimoto Member
Posts: 2267 From: South Florida,USA Registered: Jul 2003
j/k
yikes..
j/k
