[rrsteer]

Currently driving to Spiti in a 2004 Toyota Hiace. The front suspension on the driver side is making a knocking sound when driving over bad roads. Sometimes i can feel like something touches the floor too while making the knocking sound. Some other points to note:
- even on good roads but ones which have undulations, i can feel the knocking
- the steering is working fine
- overall the suspension seems to be doing its job

I know its hard to diagnose only from whats written above, but can you guide what all things can be causing this? Also what is the probability of it causing a breakdown as i will be countering bad to very bad days over the next few days. E.g. if the ball joint is causing it - how far can it be stretched before something major happens?

[Indian2003]

Originally Posted by rrsteer

Currently driving to Spiti in a 2004 Toyota Hiace. The front suspension on the driver side is making a knocking sound when driving over bad roads.

It could be the lower ball joints. Check the lower left ball joint first as that side wears first. Check for uneven wear on the front tyres. You dont say what mileage your car has done but worn shock absorber bushes can also make these noises after high mileage.

[shancz]

Originally Posted by rrsteer

- even on good roads but ones which have undulations, i can feel the knocking
- the steering is working fine
- overall the suspension seems to be doing its job

Although not very competent but yesterday during a service the mechanic had pointed out a damaged rubber "arm-bush" on my wagonR's left front suspension. It was a spherical rubber bush which had a cut on one side, the right one was fine.
He told that when the damage increases, dust/debris will get inside and will start making a lot of noise. To me this seems like your case too.
Although he might not have been able to correctly explain it but what I saw was a cut rubber bush but since he said he will change the entire arm as the bush isn't available separately. I decided to do it later since I wanted to double check that and currently its not causing any issue.

Do check it, just need to look behind your wheels and check, not sure how it looks on the Hiace though.
I am guessing and like Indian2003 said seems like the lower arm ball joint, damaged/worn out.

Just for reference, this guy is changing the the lower control arm, similar issue I guess : Credits to Providers

Auto Tales

[rrsteer]

Originally Posted by Indian2003

It could be the lower ball joints. Check the lower left ball joint first as that side wears first. Check for uneven wear on the front tyres. You dont say what mileage your car has done but worn shock absorber bushes can also make these noises after high mileage.

The van has done 220k kms. The front shock absorber was recently changed as there was a lot of uneven wear on new tyres. I believe the bushes would have been changed when the shock absorber was replaced.

Will get the lower ball joints checked tomorrow. Just asking, even if their condition is terrible can they last another 500 kms of bad to extremely bad roads without causing a breakdown? Since i can get the spare parts only from Delhi.

[Indian2003]

Originally Posted by rrsteer

Will get the lower ball joints checked tomorrow. Just asking, even if their condition is terrible can they last another 500 kms of bad to extremely bad roads without causing a breakdown? Since i can get the spare parts only from Delhi.

No problem driving a short distance with worn lower ball joints but dont speed when you dont know the amount of wear. You can easily check by jacking up the wheel and rocking it while holding at the 12 and 6 o'clock position. No negligible play should be felt.

Since you just heard the knocking sounds, it should be safe to drive to a workshop for 500 km or more.

[rrsteer]

Originally Posted by Indian2003

No problem driving a short distance with worn lower ball joints but dont speed when you dont know the amount of wear. You can easily check by jacking up the wheel and rocking it while holding at the 12 and 6 o'clock position. No negligible play should be felt.

Since you just heard the knocking sounds, it should be safe to drive to a workshop for 500 km or more.

I completed the trip safely in the van. It was indeed the ball joints and there was quite a bit of play in the driver side tyre.

On another note, I noticed that in high altitude - heights above 3000 metres - there was a lot of blue/white smoke coming out from the van. I didn't notice this in other cars/trucks. One point to note is that in the middle of the journey I added 10 litres of diesel oil from a road side vendor and I would suspect high chances of it being adulterated with kerosene. I don't know if thats what caused the white smoke, because there is no smoke from the van here in the plains.