WHEN I accelerate hard i get a knocking sound from under teh car, could it be aloose trans or engine mount, something with the drive shaft? any suggesttions?

 

Is the Torque arm loose/mounts bad? Oh, by the way, this went through twice.

 

Hey camzcruizer, I don't have an ansewer for ya but I am having the same problem,
(87 5.0 TPI, 700R4), it knocks when I take off and seems to stop when I get into OD, I had it looked at and it seems to be coming from the torque converter, (how does that break) or the pump. If you find out anything about this camzcruizer let me know, thanx.

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TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 10 bolt 3.23 g92 axle, 4 wh. disc brks.

 

I am having a hard time understanding exactly what you say it is doing, but if it is just like one hard thunk when you get on it there is a good chance that it is your tranny mount. I replaced mine and two other guys around the same time because they all happened to go bad. It is really easy to do unless any of the bolts in the subframe came unwelded (as they did on one of my friends cars) Hope this helps.

Ben

 

I'm with this guy, I had the same problem and I replaced the mount and man what a diff. It is cheap to you can get a stock replacement for like 15 buck from the auto parts store, or a good mount for $34. Change it you need to any way.


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87 Z28 305 TPI, Auto, LT-1 cam (@.50 418/430, 194/199, LSA 111), roller timing set, 2.73, Gutted air boxes, K & N fillters, Dyno Max 3" cat back, 8.8 mm spirals, air foil, BFG Drag radials,170* Stat and TB bypass.
Old Best 15.414 @ 87.47.
new best 15.006 @ 89.55.
w/ drag radails 14.6 @ 93
“Fallen But Not Forgotten”

 

No its not one thud knock but a continuing
knocking and I get it at idle until about 40mph when it goes into od, I am sure its coming from the front of the trans where the tq converter meets the trans, I was told it could be the converter or the front pump, anyone ever had this prob. and would a bad pump make this sound, it sounds similar to a rod knock but after all the seraching I am sure its not a rod knock cause its definitly coming from the trans. ?????????

------------------
TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 10 bolt 3.23 g92 axle, 4 wh. disc brks.

 

in the '76 i had a problem that made the noise of a push rod what happened was that the flywheel was warped and was knocking back and forth

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'87 Sports Coupe Camaro
-305 4bbl (LG4)
-flowmaster catback
-free mods

'76 Firebird
-355
-mild isky cam
-hooker headers
-mallory ignition
-edelbrock torquer II intake
-carter 625 afb
-eaton 3.73 posi rear end
-B&M shift kit

 

If you get it standing still then I doubt it is a mount problem. If you do, try pulling on the TV Cable and see if it changes at all. These pumps have been known to make a knocking noise and also flywheels have been known to crack too.

 

I have seen FWD (4T60-E) Torque Converters "knock" although it was more like a "snap" before, never seen a RWD do it, although I'm sure its possible.

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If you live in Southeastern US, check us out!
South East Thirdgen

1987 Trans Am 305
14.88 @ 92.81

 

Hey GM, way back when I worked in the GM dealer we would see converters come loose and 'knock'. Do they still have this problem with the LockTited bolts?

 

You mean the bolts backing off? No, don't see them much at all. Just an occassional knock from inside the converter, mostly 4T60-Es.

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If you live in Southeastern US, check us out!
South East Thirdgen

1987 Trans Am 305
14.88 @ 92.81

 

I did find 2 of the bolts from the tq converter to the flex plate loose, I put some locktite on and torqed, but it did not seem to help any, it still made knock sound.
The trans seems to shift just fine, I can not tell any performance difference just this knocking sound.
Thanks for all the suggestions, any and all are welcome.
What can break in a tq converter that my cause a noise? I seem to think my problem might be there.
or the loose bolts could have bent the flex plate, I have watched as it was running and it dosen't seem to look out of line.

------------------
TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 10 bolt 3.23 g92 axle, 4 wh. disc brks.

 

Did you look closely at the flywheel, up by the crank for lines? Also did you try the TV Cable pull test I mentioned?

 

I did look at the fly wheel and I did
have someone else look over the fly wheel
to and we could not see anything like
cracks? or anything obviously wrong.
I am going to check the TV cable
today. When you say loosen do you mean
to pull it foward as to loosen the
tension on the cable? Thanks.