Big shudder

[DANNY8]

Need a hand diagnosing a problem. Bout a month ago we chucked a new 253 and 4spd into my VB. Bout a week ago we chucked a borg warner diff under the back.

This morning the car has started shuddering when I'm trying to take off, and sometimes it shudders a bit when going back through the gears to slow down. I think it has something to do with the diff coz it seems to have a bit of backlash (ya can hear it when ya stop or take off), and when it's shuddering, the wheels seem to be wobbling around a bit.....but everything is fine after I take off.

As far as I know the diff is in ok condition, and since I've had it the worst abuse it's had is chirping 2nd gear....which I've only done a few times within the last 2 days.

Any idea's on wat it could be.

I might go check the engine mounts....they are new, but I guess a bolt could of come loose or sumfin.

[Gunns VC]

Could be a long shot but when my modulator valve was stuffed i was going through tranny oil real quick, and when there was little to none left if i needed to put my foot down the car would shudder majorly. Also when going down gears it would clunk, but this is in an auto. so maybe your tranny fluid could be low or modulator stuffed. Not sure but im probs wrong.

[holdn8]

could be your fly wheel needs machining or oil on the clutch plates

[eurekamad94]

a mate had a similar problem with his vl 308 on take off and past 150 it would shudder like all hell cant remember what it was diagnosed as will ask him when i get hold of him next

[DANNY8]

Could be a long shot but when my modulator valve was stuffed i was going through tranny oil real quick, and when there was little to none left if i needed to put my foot down the car would shudder majorly. Also when going down gears it would clunk, but this is in an auto. so maybe your tranny fluid could be low or modulator stuffed. Not sure but im probs wrong.

Thx mate....but yeah she's an Aussie 4spd. I know for a fact it's getting low tho coz the real seal is rooted, and for the last 3 nights at work I'd go to my car in the morning and see a patch of tranny oil on the ground. Bought some more 2day, so will top it up b4 I go anywhere in it.

could be your fly wheel needs machining or oil on the clutch plates

The flywheel was in good nick a few weeks back when we put it together. I have no inspection cover at the moment so I'll jump under and inspect for oil.

a mate had a similar problem with his vl 308 on take off and past 150 it would shudder like all hell cant remember what it was diagnosed as will ask him when i get hold of him next

Cheers mate, yeah mine shudders when I get up to speed as well. Dunno how qwik coz my speedo doesn't work. But yeah I rekon mines caused by the wheels not balanced (unless the previous owner had them balanced, but I bought them as a set and put them straight on), and coz we slapped a tailshaft together to suit the 4spd and borg warner diff, so more then likely it needs balancing.

Thx for the help guys. This new combo has been giving me trouble since it was put in, lots of small things seem to be going wrong all the time.

[eurekamad94]

just got a txt back and the tailshaft was warped / bent

[holdn8]

my fly wheel was fine too untill i dumped it a few times then it started shuddering got fly wheel machined problem solved.oh yeah by the way chirping second with an aussie 4 speed is not a good idea i went through 4 aussie 4 speeds doing that..they dont like it at all..

[Tom_1569]

and coz we slapped a tailshaft together to suit the 4spd and borg warner diff, so more then likely it needs balancing.

Was going to suggest tailshaft being out of whack, and since you slapped one together, it may pay to get it rebalanced. BUT an unbalanced tailshaft should shudder all the time, not taking off.
Fly is quite possible also.
Are you sure its not missing under load and feeling like a shudder? I thought my diff was ****ed a couple of times, turned out to be the EST miss-firing at 100km/h lol.

[markovr]

I spent a lot of time trying to find out why my old 6cyl lx torana with a m20 4 speed had a shudder after engine recondition/clutch change...new engine had a mild cam but I used a polution stromberg carby and dizzy ...replaced clutches twice, pressure plates ,engine mounts ,checked flywheel run out ...machined it ....never fixed it but in hindsight I think it had a miss in the engine just off idle and this stumble may have caused the engine to shake and when it was loaded like on take off it transfered the miss into a sort of on /off power delivery through the drivetrain....I reckon with the right fuel and ignition setup I could have beaten it but I ended up selling the car....should have not given up....loved the rest of the car.

[DANNY8]

Nah it's definitely not missing under load, it's too rough for that. But yeah I'm starting to lean towards the flywheel needing machining. The worst thing I do is chirp 2nd, it hasn't done any burnouts....and I also have to leave my foot on the clutch a fraction so the thrust bearing isn't noisy.....so I guess that would contribute a lot as well....as between doing that which would prolly get it pretty warm, and chirping 2nd could of just finished the job.

I've got a few things which need doing to the trans, so I think it's time to rip the motor and trans back out and fix a few things. My uncle has a lathe and I know he can machine calipers, so hopefully he might be able to machine my flywheel if it needs doing.

Thx for the help guys.

[Dayvo]

I'd be going with oil on the clutch plate or broken gearbox mount

[DANNY8]

If there was oil on the clutch plate wouldn't it just slip? BTW, the gearbox mount is new as well.

We're picking up a new motor for my brothers car in a few days, so when we pull mine out, we might put his in there (which has a t700) for a while to see how it goes, plus it will help solve where the problem is.

[Colby844]

ive had a harsh shudder on take off after changing a diff im not certain but it appeared to be the pinion bearing and after asking who i got it off he admitted to changing the guts including the crownwheel and pinion 2.6 to 3.08 he hadnt really any idea on setting these things up and yeh although everything looked and felt sweet it obviously wasnt - no whine cruised silent just a harshness when taking off.. ive also before encountered cyclic boom i think its called where at cruising speed there is vibration that comes on and off kinda like a drumming that after an expensive tailshaft sorting turned out to be the almighty turbo 400 id bought - it was stuffed! so yeh guess just be wary of any second hand stuff thats apparently ok if you cant test drive it - i have a 5litre VK just now that makes a heap of grunt and the diffs thumping real hard when changing into gear and yep she is showing signs of a harsh patch when first accelerating so im thinkin the ol diffs cop a floggin and seldom get a second thought... are your uni joints and bushes all ok?

[DANNY8]

Thx mate. Yeah uni's are ok, I bought new ones of those too and put them in last week. I checked them out b4 coz a mechanic mate rekons from wat I was describing it sounded like an end cap on one of the uni's had come off.....but nope, they're all still there, centre bearing seems ok too.

The bushes don't seem to bad. It has Nolathane bushes in a few spots, and the only real bads ones were the upper trailing arms which were as sloppy as a hooker on a sunday morning....that caused it to go all over the road when shifting into the next gear (that was with the auto), but just dug out some decent trailing arms with good bushes in them and switched them over while changing the diff over the other week.

I have heard a couple of 'not so good' bangs when I chirped 2nd a few times....sounded from the diff region. It wouldn't surprise me if the guy I bought the diff off of has done the same thing as wat happened to u. When I opened the back plate up and saw it had 3.23 gears, my first thought is that it's from a VK as the borg warner diff's in the VK's had 3.23 gears, and as far as I know, that's the only model which had the 3.23's. Then when we finished putting the diff in and took it for a run, the mofo was scrubbin bad on the 17's, which has now made me think it's a VL diff or even a VN diff, which has had a gear change. Can't even adjust the pan hard rod for clearance coz it scrubs both sides. So gonna have to lift it back up a bit to fit the 17's on....altho now chucked the 18's on the front, so next week after I finish my night shifts I'll prolly chuck the bigger spring seats in which hopefully will lift it enough to clear the 18's.

[DANNY8]

I'm 99% sure it's the clutch or flywheel now. When I take off it will be shuddering, then if I just let the clutch out it jumps a bit (due to the strain) but stops the shuddering instantly. While the clutch is in it shudders, when it's out it's ok.

Will have a suss when the motor comes out.

[Pub247]

best way to test for clutch shudder try reversing up a hill if it shudders badly need new clutch