4wd Shudder????

rubisubi · Post by **rubisubi** » Tue Nov 07, 2006 12:32 pm

Hey guys,

Was hoping someone out there might be able to offer some advice. Went 4wd on sat, the car was fine driving out about 70kays. Found the tracks and and then engaged 4wd LO then high, went over some step rough inclines and then all of a sudden the car started shuddering??? Went back to a flat surface put it in 2wd and kept driving till it was back to normal, then all of a sudden when back in 4wd it started doing it agian. Next day i replaced dizzy cap rotor and both fuel filters. Car drove great the wallah as soon as it engaged 4wd up or downhill it started shuddering again! Hard to explain bit like it was cutting out but never stalled. Its only when i got the revs and momentum up did it drive ok, but as soon as i changed up and the revs dropped it did it agian! Could this be a float level problem, fuel pump? Any advice would be greatly appreciated. Its a 1.8ltr 85 brumby too.

Cheers.

steptoe · Post by **steptoe** » Tue Nov 07, 2006 12:38 pm

shuddering as in vibration ? or engine missing shudder ? or whole drivetrain shudder ?

rings bells..... inner DOJ on one of the shafts might be falling apart, falling out of place then back in again ? and maybe a rear seeing as though when you engage the rears or the diff mount bits ??

rubisubi · Post by **rubisubi** » Tue Nov 07, 2006 12:48 pm

Probaly bit more of a engine type missing! When i finally get the revs up it it goes fine but as soon as the revs drop it starts again. I did notice a couple of times when i turned the car off then went to drive it was ok! Could this be a fuel evaporation, heating problem??? Or are they limited to the angle of the incline before the float level starts playing up????

coupe · Post by **coupe** » Tue Nov 07, 2006 6:09 pm

Try checking the play in the uni joint on the tail shaft at the diff end

SUBYDAZZ · Post by **SUBYDAZZ** » Wed Nov 08, 2006 1:40 pm

Definately a uni on the prop shaft for mine, but it should have nothing to do with the motor at all. Easy way to check is if the shuddering stops when cruising in 4WD, but in neutral / with foot on clutch.

schultzie · Post by **schultzie** » Wed Nov 08, 2006 4:52 pm

how about different diff ratios? at higher speeds he isnt noticing it id guess because less friction ... it is only a different idea

rubisubi · Post by **rubisubi** » Thu Nov 09, 2006 9:10 am

Nah im pretty sure its fuel or engine, as i was pulling out of a deep mud hole the car started vibrating/shuddering again! The car wasnt moving and i had my foot on the clutch while it was in first and low. Basically i just keep revving it hard till it feels right again. This can take up to 30 secs so im thinking could this be the fuel stabalising to normal some how???? Im stumped as to what it can be!

YouTube · Post by **El_Freddo** » Thu Nov 09, 2006 9:19 am

Are you sure you don't have a piston doing something like bouncing up and down the cylinder? I'd imagine that'd give you a good shudder until you gave it a flogging... Or does this only occur in 4wd? In that case i would cross out the engine from the list of problems. Maybe there's something wrong with your transfer gears (hi/lo), like a tooth or two missing from the lo range...

YouTube · Post by **El_Freddo** » Thu Nov 09, 2006 9:23 am

rubisubi wrote: Went 4wd on sat, the car was fine driving out about 70kays. Found the tracks and and then engaged 4wd LO then high, went over some step rough inclines and then all of a sudden the car started shuddering???
Cheers.

Why did you engage Lo then Hi at 70 k's? This could have easily damaged gears. My top speed in 5th low is somewhere near 70 (L series). This in my mind, makes the transfer gears suspect over the engine...

rubisubi · Post by **rubisubi** » Thu Nov 09, 2006 12:13 pm

Nah never said i was travelling at 70kays??? It only happens whens i go up steep hills and down again??? Mostly prominent in 4wd! On the road its fine in all conditions but 4wdriving i do go quite steep and the car does bounce around a fair bit!

steptoe · Post by **steptoe** » Thu Nov 09, 2006 1:00 pm

It's a Brumby. Whacking it into 4WD will change engine load.

If you think it is fuel, this is what I did with similar trouble.

Wait 'til tank is empty, remove sender unit/float/access hole to tank, make light to look in (matches not good here!) any filth? remove front and rear fuel filters and disconnect fuel pump from lines. Blow compressed air through front to back at each disconnect, not thru pump, get any shit blow into tank ? you'll see and hear it hit the bottom. stick rag in on wire to clean out any shit

fixed my weird unsolvable problem ages ago. think it is why they sold it !

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4wd Shudder????

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