Bent Frame Horns/trans Noise

[jim martin]

first sighn things were not good was the big amount of air inbetween my colector and body
         
you can see the amount my angle iron support bent .if you know what a chief chassis instilation for a roll cage looks like ,this is the point i had my drop links attached to
       
in the blue square i notced some buckling as well as i need someone to look under the car and put a straight edge along the frame horn at the point from the rear trans mount to infront of the torsion housing and tell me if its straight.

this is the continuation of the frame horn shot.again not sure if its curved or straight but need someone to put a straight edge from trans rear mount point to under torsion housing and let me know.

well racing FINDS AND BRAKES all week links and now i know mine.
first i need to modifie and install the drop links inboard of the header and attach them directly to the rear trans mount.i took a differant route and bolted a piece of angle iron to the bottom of my rear trans mount and dropped the links straight down figuring it would be very strong,well obviously not.as well i now know my m&h dot's grip well and the car makes alot of torque on launch . i  will modifie the rear suspension snubbers to a softer pair firm the rear shocks up and most likely a stiffer torsion bar .but first i need to fix a few other things
--as for the trans noise i now know with a helmet on you can't hear squat.
i ended up with 2 noises .near the end of the run i felt something was wrong and turned the motor off and coasted down the run out road and thats when i heard a load noise.sounded like it was coming from the right rear and sounded like a bad wheel bearing.when i stopped i got out and took a quick look around and noticed nothing , then i openned the engine lid and saw my breather wedged into my lower pulley.that was one of the noises.fingers crossed i fired it up again and  got moving again and heard the same bearing/type noise even louder as i had my helmet off this time,i sware it sounded like right rear still .now that i think about it ,THANKS FOR THE CALL BRUCE AND SORRY I HAD TO CUT THE CALL SHORT but thanks for making me think  !!                                                                                                             ----the noise was there with the engine off and coasting in neutral
--noise was there in 1/2/3 gear will driving
--louder as speed increases
--?could be my SAW axles rubbing in the axle tubes
--?could be the trans contacting or just transfering more noise into the car due to solid mounts and a new high load put on the trans by being bent in the horns?
first thing is i need to attempt a horn repare and a new road test with my rubber mounts then re diagnose the trans.
so if anyone can help with the horn straight edge test it would be a big help to start.pan is a 68

[Tom H.]

you may be hearing the R&P

[Billyisgr8]

Ouch I had the same problem with my T4,  I ended up tying into the body at the package tray since I had no roll cage to tie into.  My alternator pulley was rubbing on my deck lid and made a nice cut through it. I droped my engine approx 2 \" when the frame horns bent. I have both a swing pan and an irs pan not attached to the body now.  I can try to get some pictures of those area today after church.

Kevin

[Billyisgr8]

OK  You don't need a picture for this.

It is perfectly flat from before the torsion housing up to where the axleshafts go over the frame horns then the horns go up about 1/16\"

Any other dimensions needed it is easy for me to measure.  My pan is a 1972 swing, I'm not sure if it makes any difference.

Kevin

[silas]

the more i think about it, the more i think your trans is ok.

like you, bruce and tom have said, the noise could be a combination of all of the above. the extra load on the trans by the bent frame horns and lowered engine could be adding stress to the input shaft bearing and that could be forcing your mainshaft gears into your speed gears and all that extra noise is being transmitted through your solid mounts. is it possible aswell that if your framehorns are bent that the trans could actually be contacting the chassis somewhere where it shouldnt be and that aswell is making it extra noisy.

either way, i'm crossing fingers in hopes that the trans is allright.

[jim martin]

OK  You don't need a picture for this.

It is perfectly flat from before the torsion housing up to where the axleshafts go over the frame horns then the horns go up about 1/16"

Any other dimensions needed it is easy for me to measure.  My pan is a 1972 swing, I'm not sure if it makes any difference.

Kevin

thanks ,once i slid my straight edge back from the end of the horn  its straight from the torsion to 6-7\" before the end.so it would appear that the last bit from what i can measure is bent down 3/8\"
.i may just applie a bit of heat to that area and slid a tube over the end and pull it up.
could you do me one more favor and try to give me the exact amount its bent up at the end.should be able to do that if you could get a long enough straight edge on the rest of the frame horn.
million thanks, jim

[Billyisgr8]

.035\"  space and it starts 5\" from the frame horn end without the bolt in.

8 \" is where mine bent on my irs rear end, mine had some rust inside which was the culprit for me.  But it really colasped from that spot on both sides. very close to 2\" drop.  I used a jack with a chain around the bottom of it, and I straigtened it out close to where it was before.

Kevin

[jim martin]

thanks for the info !!!!!!!!!!!
--i tried to bend it up the other day and most likely i had everthing in the wrong spot as it didn't want to rebend up.
--i was thinking of using the torch and heating slightly at the point of the bend then trying again.
billy your a fabricator what do you think of using the tourch to warm it up?

[Billyisgr8]

I was going to add that answer to my post above, I didn't heat it up, the jack worked excellent.  Heating it up would be better.

Here is what mine looked like.  The wrinkle folded over on itself.  The culprit definitly was rust, even though I would like to say it was a good launch with great traction and lots of hp.

Oh and I'm a wood worker  I just happen to have a few metal working toys.

Kevin

[jim martin]

is the demensions you gave me from the swing axle pan?
the reason i ask is there was a 71 irs at the fuel station a few minutes ago and i took a peek underneath and the last 5-6 inches are really bent up and mine was defently not like that

[Billyisgr8]

Yes  the dimensions are from a 72 swing pan.  The IRS is a whole different shape under the bottom of the horns.

Kevin

[jim martin]

Yes  the dimensions are from a 72 swing pan.  The IRS is a whole different shape under the bottom of the horns.

Kevin

thanks again!!! for the dimensions and your time spent.
here's how i got it straightend ,after i rethought it a bit ,i decided to use the same point as the berg mid mount /applie tension to the rear frame horn one at a time of course and jack away.well it does lift the car of the rear jack stands but what your get to do is bounce the car from the rear bumper which causes the exact opposite load on the horns.
here's the set -up

and after about 30 small bounces with a few larger ones in for good measure i get mt curve back with .250 bend up so with billys measurment i need a bit more.

so if you end up in the same bad shape i was in don't worrie there is usally a way to fix things.

[Billyisgr8]

You went to far, .035\" is less than 1/16\"   not 3/8\"  Your motor will be sitting higher now. unless you can pre-load your frame horns down.

Kevin

[jim martin]

You went to far, .035\" is less than 1/16\"   not 3/8\"  Your motor will be sitting higher now. unless you can pre-load your frame horns down.

Kevin

oops !
well bending it down a bit is easy as you can use a huge lever to applie some force downwards without the car lifting.
good thing i stopped after one side.
thanks again !!

[Bruce]

I'd be a bit wary about following the measurements of Kevin's car.  The later swing axle cars use the same shock towers as IRS, so it stands to reason they used the same frame horns since the IRS versions work for both IRS and swing.
I'd be more comfortable checking out a 60s swing axle car.

[Billyisgr8]

Bruce  the swing frame horns are very different than irs horns on the 2 pans I have.  I have both sitting here upside down for easy comparison.  The irs has a flat spot on the top side where the cv's go over, the swing is round in the same spot.  Under the flat spot on the irs is a bubble down I guess to compensate for the strength lost in flattening the top side.

Kevin

[Bruce]

I had a chance to go under a 66 pan a couple of days ago, and I can confirm Kevin's findings.  The bottom surface of the two frame horns is dead straight from the torsion housing all the way back to the rear trans mount.

Jim, any updates on the repairs?