Idler pullies and belt--what else "while I'm in there?"

2006 T1N 158WB. Approaching 150K miles. I have had it for 15K miles.

Serpentine belt came off the other day. I haven't moved the radiators out of the way yet to see what else may be bad but initial inspection reveals what looks like a broken idler pulley. All other pulleys seem to spin and the alternator clutch seems to be working just fine. This seems like a good opportunity to do some preventative maint. so I was wondering what others might recommend while I'm in there. This will be my first time taking the front off to access the engine.

Alternator: Was thinking about replacing the pulley. Prev owner records show that alternator was replaced with 90A OEM at 75000 miles ago. Should I just replace the whole thing? How long do we expect alternators to last?

Tensioner: Per records never been done. I am going to replace it.

Water Pump: Per records never been done. Should I replace the whole thing or just the pulleys?

Idlers: Will replace. Especially since one is broken as far as I can tell.

Fan/Viscous clutch: were just replaced by local shop about 5000 miles ago.


Thank you!

I’d definitely do the alternator. Comes with its own new clutch. I upgraded mine to the 150A version - a bargain of preventative maintenance at a little over $200. Europarts San Diego or Amazon. Make sure it’s a Bosch.

Best of all, you’ll have a spare.

There’s a simple, clear image of the belt path on the forum somewhere.

Thanks glasseye.

Anybody have any thoughts on the water pump?

Coolant hoses, especially the one to the heater which is hard to get to: https://sprinter-source.com/forum/showpost.php?p=582809&postcount=2

Intercooler hoses may be another item

Water pump life seems about the same as the tensioner.

Clean the radiator fins

I suggest the radiator swing out method if going after a lot of stuff: https://sprinter-source.com/forum/showthread.php?t=58962

Thanks HK. Based on my inherent laziness (if I'm going to do it I am going to do it right, and once) I decided to go all in and replace pretty much all of it while I am in there and will try the swing out method.

My wife shakes her head when I start talking about spending money to save money and time. But, it's cheaper that doing it piecemeal at the local mechanic and if I am going to get this thing to 500,000 miles I am going to have to learn how to do some of this stuff at some time. Might as well be in the driveway in the winter!

A caution.

Weigh the convenience factor of extra disassembly for accessibility against the possibility of breaking parts.

If your truck is at all rusty or shows corrosion be very careful with any metal fittings to the plastic radiator tanks. They can be fragile.

vic

Aqua Puttana said:

A caution.

Weigh the convenience factor of extra disassembly for accessibility against the possibility of breaking parts.

If your truck is at all rusty or shows corrosion be very careful with any metal fittings to the plastic radiator tanks. They can be fragile.

vic

Click to expand...

Indeed, and noted, thank you.

I read your thread on water pump replacement, so I know that I can do all this tipping the radiators vs swinging them. I plan on following HK's advise on the radiator swing and starting with the trans cooler lines but not disconnecting them at the radiator. Luckily my van isn't rusty (except around the windshield but that's another project for another year) as it's been in CO and AZ its entire life.

I won't be starting this project in earnest for a few weeks, Baja is calling and thankfully our group doesn't need my van this year for the trip.

I recently changed out the idler pulleys without doing anything with the radiator and fan shroud. It was a side of the road repair and luckily I had new pulleys (that I should have replaced earlier), a used belt and a 50mm torx bit and a box end wrench to fit on the hex bit. The outer idler pulley failed and destroyed the belt. I had bought the serpentine belt kit from Europarts that comes with tensioner and idler pulleys but foolishly didn't change out the idlers as they spun just fine. 225,000 miles on idler pulleys. The tensioner was incredibly stiff and would not spring back after retracting, causing noise and belt flutter. Replaced at around 210,000 miles.

For the serpentine belt...use the locking pin or other proper tool/nail to hold the tensioner. Route the belt around all the pulleys but keep the belt off the pulley on the water pump/fan as that is the one that slides on last. I struggled for an hour before coming here to read about that simple tip.

I have never had an alternator/pulley issue - knock on wood.

My water pump sprang a leak west of Las Vegas in 110 heat at about 190,000 miles. Wish i had replaced the thermostat at the time I did the water pump.

I think my fan clutch is shot as I have never heard/felt it engage in extreme heat. It works fine lightly loaded in the low 90's that I encounter in the mid-west, but I need to change it out one of these days.

borlo said:

Thanks HK. Based on my inherent laziness (if I'm going to do it I am going to do it right, and once) I decided to go all in and replace pretty much all of it while I am in there and will try the swing out method.

My wife shakes her head when I start talking about spending money to save money and time. But, it's cheaper that doing it piecemeal at the local mechanic and if I am going to get this thing to 500,000 miles I am going to have to learn how to do some of this stuff at some time. Might as well be in the driveway in the winter!

Click to expand...

I like the way you think! I always tell people I am lazy and hate to do work twice. So My newly acquired 104K mile sprinter started leaking from the water pump today. I am going to replace most everything that comes off in the process. Water pump, hoses, thermostat, coolant, fan clutch (it think it is bad), belt, idlers.

However.....Based on my experience with the bosch alternator and clutched pulley on my VW TDI, I am going to wait on those. I think they will go to 200K. If I had 150K I might think twice.

05103580aa is the part number forthe odd shaped hose thats under the top radiator hose. Was a PITA to find online and of course the dealership has no idea what you are talking about. I'm not sure if you have already finished but if you haven't started yet, In my opinion taking the radiator, intercooler, trans cooler, and radiator brace off is definantly worth it. Especially if you are replacing hoses and other things. You can get the whole cold side factory CAC assy on amazon for like $110. Also the hot side for cheap.

5120147AA is the cold side, 5120148AA is the hot side

I am ordering everything from europarts-sd so when I get home from my trip it will all be here waiting for me.

The trans cooler connections below the radiator came apart just fine so while I haven't swung the radiators yet all the groundwork has been laid and I'm ready to go. Will start in earnest in a couple of weeks.

I would just swing the A/C condenser out of the way. That seems to be the only part that gives me trouble. The one time I tried to take it apart, I ended up needing a new condenser and both lines going from condenser.