Having trouble taking off.

[DANNY8]

Started driving around yesty with the new motor and 4spd in my VB. It has a lot of trouble taking off from a stand still, just wants to stall unless I ride the clutch a fair bit.

I even reversed into a park last night and my back wheels sat in the curb which sinks down at the back a bit, and I had to get some mates to push the car out of the curb b4 I could go anywhere lol.

Why does this normally happen? It's a rebuilt 253 with an aussie 4spd behind it.

I thought it may be the cam I got coz it's pretty big. It's a Dynotec stg 4, power range is from 2700rpm to 5700rpm. Could that be wats causing it? The diff has 2.8 gears in it too, which prolly makes it a bit harder I guess.

[Tom_1569]

That diff/cam ratio dont go together and could be part of your problem.

Check the usual first like clutch adjustment, brake/handbrake drag.

But, you have a diff which is designed to keep the car at low revs, yet your only maing power in the higher range. With that diff and 15's you should be sitting aty around 2000-2200 at 100K's from memory, so your not even making power at a cruising speed. You will also find you would be using more petrol then if you were cruising in the power range.

Im assuming you know this already, cause you've got more knowlege then me lol.

[DANNY8]

Thx for the help mate. I've got a disc brake borgy out the back which is gonna go in oneday and it has 3.23 gears, which should be a huge improvement. The reason I went with such a big cam is coz 1, I want to make the power higher in the revs, and 2 coz it's the first V8 I've had which is worked....so I would rather have one too big then too small haha. Sounds stupid but yeah I've prolly gone a bit overboard. I didn't actually realise the motor would have trouble working under the cam's power range. I figured it would be like stock, then when she hits 2700rpm it starts making the real power. Even if I mash the pedal in 1st after I start moving it doesn't go to good until the revs get up then she starts hookin.

Atleast if I'm on the highway I should have no probs overtaking lol. I even joked last night saying anyone would think I'm trying to break the land speed record by getting such a big cam and having low diff gears lol.

The clutch alignment is ok, altho the thrust bearing is a bit noisy, and the rear oil seal on the box seems shagged. I'm thinkin maybe another cause could be the spigot bearing worn out. I've bought all new replacements for those, but the thrust bearing and spigot bearing will have to wait till next time the motor and trans comes out. When we put it together it was at night and no shops were open, so we just used the old ones and hoped for the best....the clutch isn't to old anyways so thought the thrust bearing would of been replaced at the same time, but apparently not.

[Tree cutter]

It could be running a bit lean down low in the revs because the big cam will give you less vaccum at idle which means it wont suck as much fuel in.

[DANNY8]

Cheers mate. She's runnin straight gas though. You rekon the low vacuum could still be an issue with that?

I rekon I found out why it wouldn't take off out of the curb the other night...as the linkages need adjusting, I rekon it was stuck in reverse and 1st at the same time....as it's been happening a bit lately...well again yesterday when I reversed out of the drive way, and it happens going from 2nd to 3rd unless I really take my time with the gear change.

[markovr]

How about the advance curve on the distributor..has it been setup for the cam?...it could be getting the wrong timing at a critical clutch takeup point so when it gets loaded it is missing and then the engine tries to die when you slip it a bit more its what happenned to me after a cam change on my old lx torana.

With the linkages I have found in the past with a m20 in a torana I had a weld breaks or metal cracks on the shifter allowing you to push on 2 linkages at the same time but that was 1st and reverse.The internals of the 2 shift shafts in the gearbox have a lockout so you cant select 2 forward gears at the same time..so if you can something is dodgy there too.

[DANNY8]

The internals of the 2 shift shafts in the gearbox have a lockout so you cant select 2 forward gears at the same time..so if you can something is dodgy there too.

Thx for all the help mate.

I haven't been stuck in 2 forwards gears...but when changing from 2nd to 3rd it was always a bitch to get in, and I found out it was coz it wasn't coming out of 2nd properly, and I guess if it has a lock to stop it from going into 3rd if it's still in 2nd, that's prolly wat was causing it not to go in. At the moment when I go from 2nd to 3rd, I gotta shift up further then normal to pop 2nd out, then go over to 3rd and she's fine.

Any ideas on how to stop the shifter from moving over to the right and going up when she's in 1st?

[markovr]

Sounds like something is broken on the shifter...I found it cracked at a weld where the metal was the thinnest close at the top of the shifter if it moves around after you have shifted gears..also second and third inside the gearbox share a common sincro hub and rely on the hub being securely attached to the main shaft....I have heard of the snap ring coming off and the hub floating around and moving on the shaft making it hard to get top gear.
Just a quick question....do you have clearance problems using the wheels/tyres like on picture on your post...the 245 /17s scrape everywhere on the vh wagon I have

[DANNY8]

I'm gonna try and hunt down another aussie 4 speed to rebuild, but for now this one should be ok. Just hopefully it doesn't get any worse.

How my VB sits in the sig pic is ok, I've dropped it another 10-20mm since then and it rarely scrubs, just going through spoon drains and bumps. I can't have a car load tho coz it scrubs all down the road lol....pretty much can have me, a passenger in the front, and one passenger in the back and she's ok. I haven't got an adjustable pan hard rod tho, so even with just fitting one of those and I could prolly have a car load. Also I think my 17's are 235's. I had my 18's on there which are 245's and they scrub pretty bad, and that was b4 I dropped it further.

[Zeussy]

Just a quick question....do you have clearance problems using the wheels/tyres like on picture on your post...the 245 /17s scrape everywhere on the vh wagon I have

heyy there mate, just an idea, roll your gaurds, it will help alot.. did it on my vh project, with 20's, theyre only 235's but no scrubing, unless a car full..

[Zeussy]

heyy danny8, i had the same thing in my vh, it was an auto, 2.78? and put the 4speed in it, and had to ride the clutch something shocking to get it off the line, did u put the other diff in it yet??

[DANNY8]

heyy danny8, i had the same thing in my vh, it was an auto, 2.78? and put the 4speed in it, and had to ride the clutch something shocking to get it off the line, did u put the other diff in it yet??

Nah haven't put it in yet. Might do it sometime this week. Hopefully makes a big improvement.

[Zeussy]

ahh k, sweet, good luck with it, hope it works out aye..