Rebuilding the LT5 Belt Tensioner Using Guts from L98 Tensioner

[mgbrv8]

We all know our belt tensioner is rarer than a supermodel at a buffet. The GM/ACDelco part has been discontinued as have all aftermarket variants, including the one by Dayco. I had previously verified with Dayco that the L98 tensioners have the same internals as our LT5 tensioner but Dayco has since discontinued the L98 tensioner as well. You can however find an L98 tensioner in the aftermarket world and you can use the internals to rebuild the one for your LT5. FYI, Dayco still (01/24/25) makes the LT5 pulley, Dayco #89003.

Photos of OEM LT5 Tensioner, GM # 10067479

Available Parts as of 01/24/25:
L98 1988-1991 Belt Tensioner, Zip Corvette # FB-449
L98 1988-1991 Belt Tensioner, Ecklers # EK-25-112206-1
L98 1988-1991 Belt Tensioner, DRIVESTAR 10055897

I wanted to make sure to use basic tools with this rebuild so the average person could do it themselves at home. Please see the graphics I made showing the parts

Disassembly of the L98 unit w/ plastic cover is fairly straightforward:
1) The black plastic cover just pries off with a screwdriver, do so carefully, making sure to distribute force from one side to the other. (as a safety precaution I wired the unit together before prying, unsure of what would happen once the plastic cover was removed; I was pleased to find it wasn't as difficult as I thought and the wire wasn't really necessary).

2) Once the plastic cover is off, remove all the components except for the heavy duty spring and set aside in order. Then, use a chain wrench (or strong strap wrench will work) to take the tension off the spring stop.

3) Once the tension was off the spring stop, I used the wood handle of my hammer and gently tapped the spring assembly back so the stop would not make contact anymore and I could unload the spring tension.

4) Once the spring is unloaded you can remove the spring from the housing; I did this by tapping the exposed part of the spring with a hammer while also putting a screwdriver through the small hole on the backside to tap the spring.

Disassembly of the LT5 unit is only different as the cover is aluminum and tighter:
5) I used a puller with a 1/4 socket (or one a little smaller than the center pin) to press against the center pin. If you use a two jaw puller, make sure the jaws fit in the grooves. (you should be able to rent a puller from an auto parts store or buy a cheap one at Harbor Freight and grind the jaws to fit in the groves).

6) Repeat steps (2), (3), and (4) with the LT5 tensioner

Assembly
7) Replace all of the old, internal components with the new L98 ones but re-use the LT5 aluminum cover.. When you install the new spring, use a large pair of pliers or something of the sort to compress the spring slightly to get it into the housing, it doesn't take much. I also held the spring vertically to keep the Teflon tape from falling out.


David Hetrick (edited by ZBrink for added clarity)