Spartan chassis "thunking" when braking

[ULTFREQCCA]

Quote:

Originally Posted by frank1 Hi Gary, The old shocks that were on the coach were Bilsteins. I changed out to Monroe's because that's all i could find ,got them from Napa. Made no difference what so ever to improve the ride.so i am thinking that its not a shock issue, going to look at tire pressure ,run 100 psi on all 6 michlin tires. Frank.

Hi Frank -

The Bilsteins are Gas charged and the Koni's are not - IMHO that is the reason that the Bilsteins are rougher over uneven pavement and potholes. The Gas Charge effectively pushes the wheel further into the hole and thus 'hit' harder. Are the Munroe's Gas charged? I noticed a marked improvement when I switched to the Koni's and no noticable decrease in handling!

Gary

[ULTFREQCCA]

Quote:

Originally Posted by bthomforde No the wheels were not pulled.

Did yours suddenly pull to the left right after the Thunk before you had a "Good" grease job?

[frank1]

Quote:

Originally Posted by ULTFREQCCA Hi Frank - The Bilsteins are Gas charged and the Koni's are not - IMHO that is the reason that the Bilsteins are rougher over uneven pavement and potholes. The Gas Charge effectively pushes the wheel further into the hole and thus 'hit' harder. Are the Munroe's Gas charged? I noticed a marked improvement when I switched to the Koni's and no noticable decrease in handling! Gary

i am not sure, i beleve they are not gas charged becouse i read somewhere that the non-gas charged shocks were the best for motorhomes .and where i live to get shocks for my motorhome is not easy ,and napa had them instock

[ULTFREQCCA]

Quote:

Originally Posted by frank1 i am not sure, i beleve they are not gas charged becouse i read somewhere that the non-gas charged shocks were the best for motorhomes .and where i live to get shocks for my motorhome is not easy ,and napa had them instock

I just checked the Munroe website www.monroe.com and ALL the TRUCK shocks appear to be Nitrogen Gas charged! If that is the case, then you changed your shocks for the same type as the Bilsteins and that's perhaps why you didn't see an improvement in overall Ride. Since the Koni's my coach runs smooth as silk....on decent roads and after a 2000 mile break-in! BTW, Is your ride worse compared to what? If you had a solid axle front end on your previous coach, you will find that the Spartan Independant Front Suspension will hit a lot harder in the rough stuff than before, that is normal, but the IFS is also what, in IMHO, gives the better overall ride and handling that a Spartan chassis is known for.

[dukenrock]

Gary,

Not sure I noticed any improvement on braking other than I didn't have to wait and anticipate the grab! I've put over 9000 miles on the coach since the brake clean up and haven't had the problem since. I'm not sure of the logic on what side, but your theory makes sense. I dealt with this issue for a couple of years before finally having the problem explained to me. I'm happy it was as simple of a fix as it was. Hopefully that will take care of yours.

Kevin

Quote:

Originally Posted by ULTFREQCCA This is EXACTLY what my coach does....scary! Last time I had it serviced the tech adjusted the slack adjusters, but never removed the wheels to take a look at the cams and rollers....so this confirms I'm on the right track. Thank You. BTW do you notice any improvement in the overall braking since this has been rectified? I wonder if there's more of a tendancy for dust & grime build up on the passenger side because the "Step" doesn't protect the brake area as well as the enclosed compartments that are usually located just in front of the Drivers front wheel!? This would explain why it always seems to occur on the passenger side. Also, that side always travels on the dirtier side of the road..... Thanks, Gary

[carsrwayne]

2000 dutchstar i have the thunk right front when braking hard.can not find any problem.

[ULTFREQCCA]

Update -

Had the brakes checked and found the front brake drums "Blued" and the shoes cracked from excessive "Heat" - must have been done before I owned the Coach (Apr '09) b/c I always use the Jake brake when going down steep hills - that's about the only situation that causes that extreme heat.

Found the S cams in very good shape, However, the rollers had corrosion (dirt) on them - we cleaned them up and replaced the shoes and drums and now it brakes much better, doesn't pull and no more thunk!!

As a note I went for a medium grade shoe instead of the Super HD grade shoe that appears to OEM. I was told they will wear faster (maybe only 100,000 or so miles ), but will resist overheating due to the reduced metallic content.

[Roadking]

Quote:

Originally Posted by ULTFREQCCA Update - Had the brakes checked and found the front brake drums "Blued" and the shoes cracked from excessive "Heat" - must have been done before I owned the Coach .

How many miles on your coach when you had the drums and shoes replaced?? I'm having my coach checked again in early Oct for the thunking. In July I had the front end checked for the excessive right front tire wear and ball joints and everything related was checked but no problem found. Details on that are in a thread on "tire wear".

[ULTFREQCCA]

Hi Roadking -

Sorry for the delay - I just saw your question

I have 40,000 miles on the coach - no more thinking since the S-cam cleanup and the new drums and shoes. Braking has improved, but I think that I need to put the medium grade shoes on the rear to get the full benefit! I'll try that out next Spring when I get it back home for the Summer!

How did your checkup turn out?

Best Regards,
Gary

[Roadking]

One rubber boot is cracked and split and the same boot has also been damaged by technicians when they were prying on the ball joint during testing. Reyco-Graeyling specs states max allowed movement is 40-thousands and the most mine had was 10 thousands. So, I'm not changing the ball joints yet. I have attempted to seal the rubber boot to save the joint.

The rig was put on an alignment rack while the ball joints and all other pivot points were tested. The only suspected problem was a rubber bushing on the rear end. It is a bushing holding the lateral tracking arm and this bushing was compressed and the techs suggested it should be replaced.

The techs would not align the front end due uneven tire wear. Since the rig was on the alignment rack I asked what the caster/camber readings were and they refused to give them to me. They spent about 30 minutes checking things and did not charge me for the time....so I really don't know if I trust their analysis. I followed the Reyco-G test directions and confirmed the 10 thousands movement but could not spot a problem with the rear end track bar.

SO I took the rig to a Goodyear tire dealer in Col. Springs and they said my front tires were safe and would last many more miles and suggested I rotate the worn tire. I had them do this and they were fast, but they scratched my Alcoa rims.... I noticed this after I was miles down the road... and hence it's now my problem. Since the worn tire was rotated I traveled south on I-25 to Albuqurque and then west to Las Vegas. Numerous hills and hard braking opportunities. The brake clunk noise has not been heard since the tire was rotated and the tire wear seems to have stopped. So,,,, I don't know what to say .... magic????

i will continue to monitor as more miles are accumulated.