Converting a L98 tensioner to replace a 10067479 - ZR-1 Net Registry Forums

2poor4aZR1 · 04-11-2023

So I had a not so great idea of trying to convert a tensioner out of a L98 to fit my LT5. I had a free/bad tensioner from an L98, and figured why not try instead of waiting around for someone to post one. Working from pictures, I've been pretty successful with the modification, but still have more work to do. Also, I want to throw out there that this was my first time welding aluminum, and I ran a 75/25 mix when I really should have used 100% argon. While I'm not sure that any of this will be of use to most people, someone out there one day might find some use for the pictures. As mgbrv8 said 10 years ago, they are "rarer than a supermodel at a buffet" which with time will only get worse. This guide also might help with anyone needing to rebuild their old tensioner, since the process is the same for both the L98 and LT5 tensioner.

Disassembly:

I recommend spraying the inside of the tensioner and the center shaft with a liberal amount of PB Blaster the night before as the pressed on cap can be very seized up depending on where your ZR1 lives. To remove the cap, use two screw drivers or pry bars can be used on opposite sides of the cap to slowly work it off.

IMG_20230406_234740.jpg IMG_20230406_234918.jpg

Using a long bolt, nut, and washers , I capture the pivot arm and base to keep them from flying all over the place. Using two screw drivers or pry bars, separate the base from the pivot arm. Be careful and keep your fingers away from the tensioner, as the energy released can hurt you (ask me how I know).

IMG_20230410_223352.jpg

Now, if you are rebuilding your tensioner, at this point you'd take the coil spring(with the new nylon), cap spring (pt3), and plastic bearing (pt 9) from the Dayco 89298 to transplant into your 10067479 tensioner.

(Thank you mgbrv8 for this very helpful diangram)

The bearing with the cam (pt 7) is different from the one found in the Dayco 89298 (lt5 tensioner), and will need to be retained. mgbrv8 recommends removing the cam on the new one, however it does serve a purpose and shouldn't be swapped unless your original one is damaged. If it is damaged and you want to replace it, you can technically scavenge one from a Dayco 89219 (1998 Dodge Ram 3500 with 5.9 diesel). This is how I acquired mine and can confirm against the L98 tensioner that it is properly 180* out. The spring and the rest of the unit is basically scrap, so expect to spend $90 on the single part.

Modifying the L98 tensioner

Now, for the L98 tensioner, the first difference I tackled was the limit stops cast in to the pivot arm. The Dayco 89298 is clocked differently than the 89298, and will need to have the built up with weld. I used a spool gun to build up the areas, then used a file followed by a pneumatic sanding disk to clean it up.

IMG_20230407_152325.jpg

Grinder and paint makes me the welder I aint.

2poor4aZR1 · 04-11-2023

IMG_20230407_162849.jpg IMG_20230407_162845.jpg

A bunch of shaping, filing, and sanding, and the limit stops are in place thanks to a template and some geometry,

Next, I built up the stop on the base of the tensioner in the same manor as the limit stops above:

IMG_20230407_144521.jpg IMG_20230407_151329.jpg

Last modification to the pivot arm is to grind off the original stops since they are not needed. This is purely cosmetic, but I chose to do it anyway:

IMG_20230407_164044.jpg

2poor4aZR1 · 04-11-2023

Annnnnd the locating "nub" needs to be relocated to the other side of the mount, and the old nub cut off

IMG_20230408_111759.jpg IMG_20230408_112943.jpg

At this point, the center shaft of the base needs to have the keyway for the spring moved. Unfortunately I couldn't find any pics on the form of the inside of the tensioner (it was hard just finding pictures of the back of the unit), and this hasn't been done. I'll update this section when I get my hands on either an OEM unit to model or a picture of the inside.

[Reserved for future use]

2poor4aZR1 · 04-11-2023

Assembly

Start by apply a generous amount of graphite lube to the plastic bearing and base.

IMG_20230409_094734.jpg

Installation of the coil spring is pretty easy, but I'd advise against using a large pair of pliers. I ended up putting the coil spring in my vice to compress it, then used a zip tie to keep it coiled up. I very carefully then press the spring into the housing. To fully seat it, I used a rubber mallet.

IMG_20230409_102311.jpg IMG_20230409_102319.jpg IMG_20230409_123357.jpg

2poor4aZR1 · 04-11-2023

Now, you'll need to align the coil spring with the keyway in the base. Don't press it on all the way yet.

IMG_20230410_233401.jpg IMG_20230410_233518.jpg

Once started, you'll need to rotate the pivot arm, while compressing the two together. If you have trouble with this, use an old leather belt to hold the base in the vice , and a half inch drive ratchet to turn it while lightly tapping it with a rubber mallet.

2poor4aZR1 · 04-11-2023

I uploaded the entire album to Imgur in case there is any other pictures someone might need when either attempting this modification or rebuilding their tensioner.

https://imgur.com/a/7GEORgX

At this point I can't move forward until I can see what the inside of a LT5 tensioner looks like. I have a post in Parts for sale and will keep an eye open for anyone parting out an LT5.

Also offering to rebuild someones if they let me borrow it to take measurements

HAWAIIZR-1 · 04-12-2023

If you don?t find someone by the weekend, I have one I can ship to you to use and rebuild. I am out of country until this weekend.

Sent from my iPhone using ZR-1 Net Registry

2poor4aZR1 · 04-12-2023

So far the two people I've bought parts from haven't had a spare one. I'll let you know if I can't get my hands on one.

Thanks you for the help!

2poor4aZR1 · 04-15-2023

Quote:

Originally Posted by HAWAIIZR-1

If you don?t find someone by the weekend, I have one I can ship to you to use and rebuild. I am out of country until this weekend.

Sent from my iPhone using ZR-1 Net Registry

Hey @HAWAIIZR-1

Tried sending you a PM, but your inbox is full. Are you still open to sending your tensioner to me for a rebuild?

HAWAIIZR-1 · 04-15-2023

Quote:

Originally Posted by 2poor4aZR1

Hey @HAWAIIZR-1

Tried sending you a PM, but your inbox is full. Are you still open to sending your tensioner to me for a rebuild?

I cleared out my inbox. I?ll look for it tonight or tomorrow AM. I?m on the road until tonight.

Sent from my iPhone using ZR-1 Net Registry

04-11-2023	#1
2poor4aZR1 Join Date: Mar 2023 Location: Texas Posts: 34	Converting a L98 tensioner to replace a 10067479 So I had a not so great idea of trying to convert a tensioner out of a L98 to fit my LT5. I had a free/bad tensioner from an L98, and figured why not try instead of waiting around for someone to post one. Working from pictures, I've been pretty successful with the modification, but still have more work to do. Also, I want to throw out there that this was my first time welding aluminum, and I ran a 75/25 mix when I really should have used 100% argon. While I'm not sure that any of this will be of use to most people, someone out there one day might find some use for the pictures. As mgbrv8 said 10 years ago, they are "rarer than a supermodel at a buffet" which with time will only get worse. This guide also might help with anyone needing to rebuild their old tensioner, since the process is the same for both the L98 and LT5 tensioner. Disassembly: I recommend spraying the inside of the tensioner and the center shaft with a liberal amount of PB Blaster the night before as the pressed on cap can be very seized up depending on where your ZR1 lives. To remove the cap, use two screw drivers or pry bars can be used on opposite sides of the cap to slowly work it off. IMG_20230406_234740.jpg IMG_20230406_234918.jpg Using a long bolt, nut, and washers , I capture the pivot arm and base to keep them from flying all over the place. Using two screw drivers or pry bars, separate the base from the pivot arm. Be careful and keep your fingers away from the tensioner, as the energy released can hurt you (ask me how I know). IMG_20230410_223352.jpg Now, if you are rebuilding your tensioner, at this point you'd take the coil spring(with the new nylon), cap spring (pt3), and plastic bearing (pt 9) from the Dayco 89298 to transplant into your 10067479 tensioner. (Thank you mgbrv8 for this very helpful diangram) The bearing with the cam (pt 7) is different from the one found in the Dayco 89298 (lt5 tensioner), and will need to be retained. mgbrv8 recommends removing the cam on the new one, however it does serve a purpose and shouldn't be swapped unless your original one is damaged. If it is damaged and you want to replace it, you can technically scavenge one from a Dayco 89219 (1998 Dodge Ram 3500 with 5.9 diesel). This is how I acquired mine and can confirm against the L98 tensioner that it is properly 180* out. The spring and the rest of the unit is basically scrap, so expect to spend $90 on the single part. Modifying the L98 tensioner Now, for the L98 tensioner, the first difference I tackled was the limit stops cast in to the pivot arm. The Dayco 89298 is clocked differently than the 89298, and will need to have the built up with weld. I used a spool gun to build up the areas, then used a file followed by a pneumatic sanding disk to clean it up. IMG_20230407_152325.jpg Grinder and paint makes me the welder I aint. Last edited by 2poor4aZR1; 04-11-2023 at 12:57 AM.

04-11-2023	#2
2poor4aZR1 Join Date: Mar 2023 Location: Texas Posts: 34	Re: Converting a L98 tensioner to replace a 10067479 IMG_20230407_162849.jpg IMG_20230407_162845.jpg A bunch of shaping, filing, and sanding, and the limit stops are in place thanks to a template and some geometry, Next, I built up the stop on the base of the tensioner in the same manor as the limit stops above: IMG_20230407_144521.jpg IMG_20230407_151329.jpg Last modification to the pivot arm is to grind off the original stops since they are not needed. This is purely cosmetic, but I chose to do it anyway: IMG_20230407_164044.jpg Last edited by 2poor4aZR1; 04-12-2023 at 11:17 PM.

04-11-2023	#3
2poor4aZR1 Join Date: Mar 2023 Location: Texas Posts: 34	Re: Converting a L98 tensioner to replace a 10067479 Annnnnd the locating "nub" needs to be relocated to the other side of the mount, and the old nub cut off IMG_20230408_111759.jpg IMG_20230408_112943.jpg At this point, the center shaft of the base needs to have the keyway for the spring moved. Unfortunately I couldn't find any pics on the form of the inside of the tensioner (it was hard just finding pictures of the back of the unit), and this hasn't been done. I'll update this section when I get my hands on either an OEM unit to model or a picture of the inside. [Reserved for future use]

04-11-2023	#4
2poor4aZR1 Join Date: Mar 2023 Location: Texas Posts: 34	Re: Converting a L98 tensioner to replace a 10067479 Assembly Start by apply a generous amount of graphite lube to the plastic bearing and base. IMG_20230409_094734.jpg Installation of the coil spring is pretty easy, but I'd advise against using a large pair of pliers. I ended up putting the coil spring in my vice to compress it, then used a zip tie to keep it coiled up. I very carefully then press the spring into the housing. To fully seat it, I used a rubber mallet. IMG_20230409_102311.jpg IMG_20230409_102319.jpg IMG_20230409_123357.jpg

04-11-2023	#5
2poor4aZR1 Join Date: Mar 2023 Location: Texas Posts: 34	Re: Converting a L98 tensioner to replace a 10067479 Now, you'll need to align the coil spring with the keyway in the base. Don't press it on all the way yet. IMG_20230410_233401.jpg IMG_20230410_233518.jpg Once started, you'll need to rotate the pivot arm, while compressing the two together. If you have trouble with this, use an old leather belt to hold the base in the vice , and a half inch drive ratchet to turn it while lightly tapping it with a rubber mallet. Last edited by 2poor4aZR1; 04-12-2023 at 11:20 PM.

04-12-2023	#7
HAWAIIZR-1 Join Date: May 2010 Location: Japan Posts: 3,543	Converting a L98 tensioner to replace a 10067479 If you don?t find someone by the weekend, I have one I can ship to you to use and rebuild. I am out of country until this weekend. Sent from my iPhone using ZR-1 Net Registry __________________ Craig "ZR-1 NO KA 'OI" "ZR-1 ICHIBAN" 1995 #228 Black/Black with Dunn Heads ZR-1 owner since September 2003 ZR-1 Net Registry Founding Member #0074 NCM Lifetime Member #2048 Last edited by HAWAIIZR-1; 04-13-2023 at 01:37 AM.