My terminology and years are not exact... but hopefully I am being clear enough.

It's my understanding that pre '92 or so 3.0 engines have a mechanical spring/ pulley for placing tension on the timing belt. After '92 or so Toyota went with a hydraulic setup of sorts.

1. Is the hydraulic setup better, more consistent?
2. Can one retro-fit the hydraulic setup onto an older engine?

I believe I am having an issue with the tension on my timing belt and instead of just replacing the spring I thought the hydro unit might be a better option.

Thanks

 

I thought they were all 'hydralic'. It's been a number of years since I've been inside it, but if memory serves this device is more like a gas shock than anything else. Once the tension is applied you lock it down.

Perhaps someone else who's memory isn't dating back 5+ years can answer more accurately.

 

No. On post '92 3vze it's hydraulic like what you describe monster maxx, but from '89 to 91 it uses a roller which is tensioned with a beefy spring. Pics coming

 

check out my thread in my signature for pics of the 93 and older hydraulic. It has 2 bolts through the fan housing, the older one only uses one bolt - so fabricating would require several parts and I am not sure it can be done.

 

My 91 was hydralic same as the 94, no big spring in either one.

 

my 91 was spring and my 95 was hydrolic and we did change my 95 to the spring we like it better nad it is not hard the boss on the head for the pivot point of the roller is still on the head you just need to buy the roler the spring and the hook that bolts onto the waterpump to keep the spring in tension it is nto hard atall i wish i had pics to show you from when we did it sorry!

 

this is what my 92 4runner looks like



The hydrolic ones have nothing you "lock down" its a gass pressure shock thingie...

if your fan bracket supports it (ie has the spot in the casting for it) you can change to the hydrolic version if you want. (you'll also need the diffrent tension roller also)

 

Beat me to it SnapOn!! But yeah mine looks JUST like that!

Might your truck be a 92 to toyota but built in late 91?

My 1990 4runner has a production date of 8/89, my truck turned 17 last month! Itll soon be celebrating that bday with a good burn out!

 

I'm waking up this dead thread because of a problem (resolved) that I had with RockAuto.com, and because there seems to be a little confusion here about which idler goes in which years. And because this is the top match while searching for the problem on Google.

I did a 'part number to application models' search in the Toyota EPC on both the hydraulic and spring tensioner models. Guessing, it appears that 1993 and later year models have the hydraulic tensioner, and 1992 and earlier have the spring tensioner. Better is to go by manufacture date, and here is what the EPC says:

13505-65040, "idler sub-assy, timing belt, no.1" with hydraulic tensioner assembly: In 4Runners starting from manufacture date 05/1992, and T100s from 08/1992.

13505-65020, "idler sub-assy, timing belt, no.1" with spring tensioner: In 4Runners up to manufacturing date 08/1992.

MonsterMaxx must have had an engine transplant to have had a hydraulic tensioner in his '91.

There are a few months of blur in there, but you can always check the right side of the fan bracket for the hydraulic tensioner assembly.

Issue with RockAuto was that I bought a #1 timing belt idler that was listed in the Toyota/1995/4Runner/3.0L section. It turned out to be the spring tensioner type. This part clearly doesn't apply to the '95 model, but RockAuto pointed out that I overlooked the words 'w/spring tensioner' in the description. They took the part back, but I lost out on the return shipping.

One of the customer service guys there, Patrick, was pretty helpful with it, even called Gates, the manufacturer, about it. He gave me a lot of details about what happened and took care to answer all of my questions, and I've read RockAuto is a good shop with good products here on the forums, so I was willing to go back to order the correct parts.

I still hope they'll fix their catalog so the next person doesn't make this mistake, and I still wish they'd given me a free shipping discount on the replacements.