49 F1, newly rebuilt flathead v8 3spd light duty tranny, new clutch kit,new pilot and throwout bearings, PP, C plate. 9" rear put in 2 years ago (3.50). new driveshaft made up for new rear, new universals. used a shim to set angle of the rear end parallel to the engine. i had the shudder prior to and after the new driveshaft and rear end. i was blaming it on the clutch which indeed was warn and splitting (which i am learning is prob not the cause of shudder). it persists now ever with the total new clutch kit and turned fly wheel. i'll start by checking the u-joints and rechecking the angles. any insight is welcome. dick r.

 

Try this: don't baby the clutch. Slip it more than needed at every opportunity for 100 miles. These are heavy-duty clutches and they need to be broken in. Mine has been in there for 6 yrs and when I pulled my engine the machining marks on the flywheel were all still there except for a few spots around the edge. I've just been too gentle on it.

 

How are the engine and trans rubber mounts? Clutch linkage in good shape?

 

the front motor mounts are virtually new, the tranny mount seemed to be fine. we've had the clutch linkage out, it's a little worn, we'll take a look at that and do some clutch slipping too. as of now, i give it some gas and power through it quickly, only prob comes in tight spots in parking lots, etc. everything else is working great, can't compain. dick r.

 

My 56 had the same symptoms in first and reverse when the clutch started to engage. Took me a couple years to determine the front motor mount bolts were not correct. The bolts were tight but the bolts were only threaded for about 1/2" when they needed to be threaded for 5/8". I blame it on the previous owner like the other items he gets credit for.

 

I tend to side with Ross's analysis on this, when I changed out trannys to the T5 I discovered that even after at least a 1000 miles (no real idea when the PO might have done it) my stock clutch disc still showed the factory paint (QA mark) on the friction surface. I've worn out clutches behind little 302's and tend to baby the clutch cause I hate all the work of replacing em...

I put up with the shudder for a 100 miles or so after changing the T5 in, then figured out that if you are a little less gentle it shudders a whole lot less.. After 500 miles it's really settled down.

 

I take from your explanation that the 'shudder' is as the clutch is engaging and before the driveline starts to turn. Don't over look the possibility of the transmission and bell housing not being parallel with the flywheel.

 

ok, based on feedback from here and having a couple of people drive the truck, i'm going to start with a new transmission mount. the front mounts are fairly new, rear looked ok, but?? i have learned how to get going most of the time with little or even no vibration. done improperly, it can really shake the truck. since the issue goes back to the previous engine, clutch to this engine, clutch, it must be something that hasn't changed. i'm fine with replacing the tranny mount even if it is not the complete solution. expecting it in the mail friday.

 

In all honesty.. sounds like the flywheel might need to be machined (didnt see it listed in the post)

If it was hot spotted and not trued, then that will for sure cause the shudder. It will be most noticeable when starting from a dead stop. slipping the clutch more will cover that up, however, it will ruin the new clutch and pressure plate

 

we did have the flywheel resurfaced, although i hadn't mentioned it. i'm going ahead with changing the rear tranny mount (just because it looks really ugly) and it also looks like the front of the engine is a little off center to the right in the motor mounts, we'll lever that over when we do the tranny mount. i can launch it fairly well with sufficient gas. the problem comes when you get a vibration and inadvertently make it worse. we'll check everything we can, pinion angles, etc. am also looking into ross's research in a mis-match between bell housing, starter plate. i'll report back any news. thanks for all the suggestions. dick r.

 

ok, ready to put this thread to rest. i installed a new transmission mount (with some consult time from ross). my old one had completely separated. i still have a little shudder at start in 1st, but much more manageable. no bone shattering vibration i got ocassionally before. i also managed to center my engine in the front motor mounts, they had been off by 1/4" before. my remaining shudder may be new clutch break in, maybe something else. much improved though, having a transmission mount actually attached to the truck. thanks to all who contributed ideas.

 

glad to hear it all worked out.

Let us know if the shudder gets better or worse with time.

sidenote, you arent feeling an engine misfire and mistaking it for a driveline vibration/shudder correct? not to insult you intelligence but I have seen this happen before.

 

mustang mike, the rebuilt engine seems to run perfect. it runs strong through all the gears, delightful. i also can start in 1st some of the time with no shudder, just have to fine tune my release. i will update later if it goes away entirely. thanks for your suggestions, dick r.

 

That's great Dick! Now rack up some miles on that like-new truck!

 

ross, i'm driving it on a daily basis and loving every minute of it. now if i'm going 40mph and it hit the gas, something happens.