Rebuilding the LT5 Belt Tensioner Using Guts from L98 Tensioner [Archive]

View Full Version : Rebuilding the LT5 Belt Tensioner Using Guts from L98 Tensioner

mgbrv8

12-04-2013, 02:28 PM

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 (https://www.zr1.net/forum/showpost.php?p=338181&postcount=11)

Available Parts as of 01/24/25:
L98 1988-1991 Belt Tensioner, Zip Corvette # FB-449 (https://www.zip-corvette.com/88-91-serpentine-drive-belt-tensioner-correct.html?gad_source=1&gclid=Cj0KCQiA7se8BhCAARIsAKnF3rxGca9jc2IuyPDGeIvI eG4o_qhUmFtU15RUq5AARaeNp0U06N8lYesaAqqhEALw_wcB)
L98 1988-1991 Belt Tensioner, Ecklers # EK-25-112206-1 (https://www.ecklers.com/1988-1991-corvette-engine-belt-tensioner-25-112206-1.html?utm_source=google-pla&utm_medium=shopping&T5_Var2=shopping&utm_campaign=Corvette+(1953-1996)+Vehicle+Medium+LTVMiddle&intl=0&dialogtech=ppc&gad_source=1&gclid=Cj0KCQiA7se8BhCAARIsAKnF3rybn1_K7hApT7IeZHl3 taKRo8x5dLIG7Wnx_nMEEDCgdPpSh5MHgSkaAoiZEALw_wcB&gclsrc=aw.ds)
L98 1988-1991 Belt Tensioner, DRIVESTAR 10055897 (https://www.amazon.com/DRIVESTAR-OE-Quality-Tensioner-Chevrolet-Corvette/dp/B073W9K1V3/ref=asc_df_B073W9K1V3?mcid=1129cd507be53c8e8fdd2e6 145b31eec&hvocijid=13548285650707846878-B073W9K1V3-&hvexpln=73&tag=hyprod-20&linkCode=df0&hvadid=721245378154&hvpos=&hvnetw=g&hvrand=13548285650707846878&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1027067&hvtargid=pla-2281435178098&psc=1)

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)

GOLDCYLON

12-04-2013, 02:33 PM

Nice project well done :cheers:

Any thoughts of doing a run of these? Im sure they would sell quick. I would be in for a spare

mgbrv8

12-04-2013, 02:42 PM

I don't have any used ones to rebuild, and you cant find them. BTW here is the link to the cheapest Dayco L98 tensioner I could find.

Dave

(01/24/25 - Part has been discontinued; ZBrink)

-=Jeff=-

12-04-2013, 04:13 PM

I have a used one I need to rebuild...

GOLDCYLON

12-04-2013, 04:22 PM

Im thinking the same I think I have used one as well

mgbrv8

12-04-2013, 05:33 PM

Ill tell you what if one of you guys buy the new Dayco and mail me it and you old one I will rebuild it and mail it back for the one that is on you car now. I have a good friend in Japan with a Z that's been down cause of catastrophic failure of his ZR1 tensioner. That way I can rebuild the traded one you give me so I can rebuild it and gift it to him. A perfect brotherhood circle.

Dave

We Gone

12-04-2013, 06:36 PM

This is the other option.

http://zr1specialist.com/HAT%20Web/products/accessory%20belt%20tensioner.htm

mike100

12-04-2013, 08:14 PM

Gonna have to try this. I have one with 30k on it that sometimes sticks a little, but isn't completely worn out. I was able to buy one of the last new ones for $199 and was happy to get it at the time.

Dynomite

12-04-2013, 08:36 PM

So I ordered a new Dayco tensioner from rock auto with a discount coupon and came out to a total of $38 and it came with the pulley with the belt guides so that was handy because all you can bye right now is the smooth pulley.

The below linked Belt Tensioner Pulley will fit the ZR-1 (LT5) as well as a standard C4 with L98 engine.
1986-1993 MUSTANG 5.0 GT Billet Aluminum Belt Tensioner Pulley
3.5" Lip OD. x 3.25" OD. Belt x 1" W Belt with 6203RS (https://www.ebay.com/itm/290580284103?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

See item #8 LT5 Added Systems (http://forums.corvetteforum.com/c4-zr-1-discussion/2942569-tech-info-lt5-eliminated-systems.html#post1579114180)

mgbrv8

12-04-2013, 09:35 PM

Wow!!!! $57 bucks. But it will work.

Dynomite

12-04-2013, 09:47 PM

Wow!!!! $57 bucks. But it will work.

It runs sooooo smoothly and is sooooo Bling :D

mgbrv8

12-05-2013, 02:27 AM

Dynomite Have I mentioned lately that you rock :cheers:

We all know our belt tensioner's are rarer then a supermodel at a buffet. You can't find a new or old one at almost any cost so I started looking into rebuilding mine. I wanted to make sure to use basic tools with it's rebuilt so the average person could do it themselves at home. Our tensioners are made by Dayco. So I called them and got in contact with a wonderful guy named Randy. He verified my thoughts that the L98 tensioners have the same internals as our tensioner. So I ordered a new Dayco tensioner from rock auto with a discount coupon and came out to a total of $38 and it came with the pulley with the belt guides so that was handy because all you can bye right now is the smooth pulley. And I disassembled it first. The disassembly of the new unit with plastic cover is fairly straightforward the black plastic cover on the new one just pyres off with a screwdriver carefully and making sure to distribute force from one side to the other. As a safety precaution I made sure sure to wire the unit together because I wasn't sure what would happen once the plastic cover was removed I was pleased to find that it wasn't as difficult as I thought it would be and really the wire wasn't really necessary but it's a good precautionary measure. Once the plastic cover and the dampener pad and dampener spring was removed and set aside I used a chain wrench to take the tension off the stop. Once the pressure was off I could use the wooded handle of my hammer and gently tap the spring assembly back so the stop would not make contact anymore and I could unload the spring. Once the spring was unloaded all you have to do is remove the spring from the housing I did this by tapping the exposed part of the spring with a hammer and on the other side of the housing is a small hole on the back that I put a screwdriver through to tap the spring. Disassembling the old unit is only slightly different the cover which is plastic on the new one is aluminum on the old one and a litte tighter so I used a puller. I use the small quarter inch socket just a little smaller then the Center pin to press against. If you're going to use a two jaw puller make sure the jaws fit in the grooves you should be able to rent one from an auto parts store or buy one at Harbor freight and grind the jaws to fit in the groves. The rest is just replacing the old or components with the new ones. One note needs to be made though 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 doesn't take much and I held the spring vertically to keep the Teflon tape from falling out.

Here is a link to all the photos of the process
https://www.facebook.com/media/set/?set=a.10203217751111467.1073741834.1439230280&type=1&l=bb4f436b0a

David Hetrick

Jagdpanzer

12-29-2013, 04:18 PM

Just finished up rebuilding my tensioner with help of these instructions and all went well. Thanks again David for posting this up for the benefit of the Brotherhood.

mgbrv8

12-29-2013, 04:57 PM

My Pleasure Jagdpanzer im so grateful it was helpful. How was the condition of all the bearings and dampener and spring?? Any pics?

Dave:saluting::cheers:

Jagdpanzer

12-29-2013, 08:01 PM

Here are the parts replaced from the doner:

http://i540.photobucket.com/albums/gg333/pwasinger/photo2_zps389ba85f.jpg

The finished tensioner:

http://i540.photobucket.com/albums/gg333/pwasinger/photo3_zps4d3172ac.jpg

The puller and insert I used to remove the cover:

http://i540.photobucket.com/albums/gg333/pwasinger/photo4_zps35d3b5e2.jpg

mgbrv8

12-29-2013, 08:05 PM

Great job wonderful work Sir

HAWAIIZR-1

12-30-2013, 05:28 AM

Dave,

You are too awesome and more than any words could say. Thank you for taking the time to document this.

Craig

mgbrv8

12-30-2013, 02:42 PM

Craig thank you so much that means a lot. I just see in the future of our cars a lot of very scarce parts. And I'm use to repairing abnormal or very rare parts, right now I'm dissecting a secondary actuator to see what we can do about that when they become scarce. Thank you again for the kind words.

Dave:cheers:

HAWAIIZR-1

12-30-2013, 04:51 PM

There are so many smart folks like you in the Registry that help to keep this dream alive. I can only imagine the time it took you do document this and take all the photos so it is greatly appreciated. There are a lot more secrets out there, but not are all being shared like you took the time to do. I wish I could contribute like this and maybe one day a light bulb will turn on for me. Thanks again!! :cheers:

Craig :handshak:

Schrade

12-30-2013, 05:29 PM

How many miles did you have on it? Was it done? Or are you just re-working it?

Good idea on the remote cam too - now I need one with 'fingers'...

mgbrv8

12-30-2013, 08:35 PM

Um??? Well I had 88k on mine. Im not sure about it being done?? Remote Cam?

Dave:fahne:

secondchance

11-16-2014, 11:30 AM

Thanks Dave! I need a replacement tensioner and was ready to spend $138. Phil reminded me of this thread yesterday at the WAZOO get together and since WAZOO have all sorts of old parts inventory (Capt. Jim unlike me saves all worn-out parts), ordered two Dayco L98 tensioners for $79 including shipping. Soon we will have 2 new, fresh tensioners. What a resourceful bunch!!!

mgbrv8

11-16-2014, 12:34 PM

That's wonderful Secondchance. I'm very glad the information Was helpful. If you need the artical Mark and I did on the news letter that can be found on the members only section of the registry website. It brings me great joy to know that it has been helpful and please post about your progress if you can. Nice thing about those L98 Dayco tenioners is that they come with the good pully with the guilds on the sides instead of the smooth one.

David Hetrick

1LEZ

07-09-2017, 08:16 AM

I just used this thread to rebuilt mine. Perfection! Works like a charm!

mgbrv8

07-09-2017, 07:21 PM

I just used this thread to rebuilt mine. Perfection! Works like a charm!

1LEZ (http://zr1.net/forum/member.php?u=4144) that so great Im so glad. Thank you for the kind words

David Hetrick

RussMcB

10-28-2019, 12:51 AM

FYI, after an evening of Googling I have not been able to locate a Dayco 89298 (L98 tensioner for rebuild parts).

Well, I did get a few hits for places saying it can be drop shipped but expected delivery is two months away.

Maybe I'll contact Marc or Jerry tomorrow to see if either has one or leads.

secondchance

10-28-2019, 08:42 PM

If you run a search for 1991 corvette belt tensioner a few new tensioners do pop up. Non Dayco though...

RussMcB

10-29-2019, 10:23 AM

If you run a search for 1991 corvette belt tensioner a few new tensioners do pop up. Non Dayco though...Thanks. I guess it's possible the non-Dayco tensioner would have the parts needed to rebuild the stock Dayco tensioner.

If I buy one and try it I'll come back here and post results.

owwdee

03-16-2020, 12:51 AM

I found on RockAuto AC Delco 10055897 for the L98 (Discontinued as of 01/24/25). Same internals, correct pulley and also had the aluminum cover which was good for me because my original cover chipped when using a puller to remove it.

Didn’t suspect anything wrong with my original at 41k miles, but since I had the radiator and fans out, figured it was worth it. Took mine apart to find that the wear plate under the cover was completely gone, only the little tabs left. Also the spring was a little weak, I could operate the tensioner by hand. Swapped over new parts following this thread. Good as new!

Ccmano

03-16-2020, 12:00 PM

Don’t suppose you have a how to or pics? Good tip either way!

Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

Just go to page 1 of this thread....;)
H
:cheers:

Corvette95

03-16-2020, 05:17 PM

Just go to page 1 of this thread....;)
H
:cheers:

Duh! Thanks, I don't know how I missed that. Great info....thanks again! :salute:

Ccmano

05-25-2021, 12:18 PM

Dave.... your Facebook link is down. Where can we find the more complete instructions you posted there?
Thanks
H
:cheers:

albeR/To

08-06-2022, 11:57 AM

Dave.... your Facebook link is down. Where can we find the more complete instructions you posted there?
Thanks
H
:cheers:

Yep, facebook link is definitely down.
I'm ordering the parts to rebuild my tensioner and these infos/pics might come handy.

tiegsd

08-09-2022, 11:16 PM

Great post, going to have to do this soon, super helpful!

Erik

08-10-2022, 03:13 PM

Looks like Dave hasn't been on in a few months. I hope all is ok with him. Anyone know him in the outside world?

A1990

08-10-2022, 05:07 PM

I will reach out to David

Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

ManPro

06-10-2023, 07:28 PM

davids1978

01-13-2024, 12:53 AM

I attempted this tensioner rebuild and cracked my back casing on the factory LT5 Tensioner while trying to tap the fresh tension spring in. I've called all around and nobody has a used/core available for sale.

I just installed a slew of new parts including injectors, radiator, ignition coils, starter, cam sensor, and knock sensor to get my ZR-1 Back up and running and now I'm dead in the water since I can't get a replacement tensioner.

Can anyone give me some guidance on how to compress the spring to fit in into the housing? I'm trying to practice installing the spring back in the L98 Donor Part casing, and I've used a vice, and a set of 20" Pliers to try and compress it and no matter what I do I can't get it compressed enough to fit back into the casing...

I just finished rebuilding my tensioner with these instructions and a L98 tensioner purchased from Amazon - fairly straightforward task.

ManPro - I ended up putting the spring in a vice with half of the width of the spring exposed. This allowed me to compress it enough to get the cover started. Once you get it started you can remove it from the vice and use a pair of channel grips to fully seat the spring.

ZBrink

04-07-2024, 02:10 PM

secondchance

04-07-2024, 09:56 PM

Does anyone have the current part # for the L98 tensioner? Everyone seems to be out of stock of the Dayco 89298 which makes me think it may have been discontinued. Or, does anyone know of another tensioner that has the same "guts"?

A bit pricey but?
https://www.ecklers.com/1988-1991-corvette-engine-belt-tensioner-25-112206-1.html?utm_source=google-pla&utm_medium=shopping&T5_Var2=shopping&utm_campaign=Corvette+(1953-1996)+Vehicle+Medium+LTVMiddle&intl=0&dialogtech=ppc&gad_source=1&gclid=Cj0KCQjwiMmwBhDmARIsABeQ7xQ5BiLbHNo7HvN5k01J iH9yXmJjDHIYwAI2Vq2Zvoub59maH3mJSGMaAiUfEALw_wcB&gclsrc=aw.ds

Dynomite

04-09-2024, 01:07 AM

A bit pricey but?
https://www.ecklers.com/1988-1991-corvette-engine-belt-tensioner-25-112206-1.html?utm_source=google-pla&utm_medium=shopping&T5_Var2=shopping&utm_campaign=Corvette+(1953-1996)+Vehicle+Medium+LTVMiddle&intl=0&dialogtech=ppc&gad_source=1&gclid=Cj0KCQjwiMmwBhDmARIsABeQ7xQ5BiLbHNo7HvN5k01J iH9yXmJjDHIYwAI2Vq2Zvoub59maH3mJSGMaAiUfEALw_wcB&gclsrc=aw.ds

But nice :thumbsup:

geezer

04-09-2024, 08:05 PM

Ecklers claim this to be correct for LT5. Can anyone confirm this??
(Ecklers current in-stock tensioner does NOT fit the LT5, you can however use the guts to rebuild yours - ZBrink)

secondchance

04-09-2024, 10:11 PM

hotroddaddyo

04-09-2024, 10:37 PM

The link posted to Eckler's website claims to fit both.... base and ZR-1.
(Ecklers current in-stock tensioner does NOT fit the LT5, you can however use the guts to rebuild yours - ZBrink)

Russ

12-10-2024, 03:35 PM

Winter projects on the Z, will include a tensioner rebuild for my 91 @ 64,000 kms and upon reviewing this thread all the knowledge one requires has been shared by those who went before as expected, thanks guys for making it possible for the rest of us. Has anyone actually verified the Eklers claim of fitting the LT5 or is it still a donor part we are dealing with?

chopped39

01-13-2025, 09:46 PM

ZBrink

01-13-2025, 10:08 PM

Dynomite

01-14-2025, 03:37 AM

L98 Belt Tensioner Conversion (https://www.zr1.net/forum/showthread.php?t=34691&highlight=Dayco+89298)

Mark Haibeck Reconditioned Belt Tensioner (http://zr1specialist.com/HAT%20Web/products/accessory%20belt%20tensioner.htm)

Google Says......
The belt tensioners for a 1990 and 1995 ZR1 Corvette are considered the same, as there were no significant design changes to the belt tensioner system throughout the C4 Corvette ZR1 production run from 1990 to 1995; meaning you can generally use a replacement belt tensioner from any year within that range on either car.

The ZR1 Belt Tensioners (1990-1995) apply pressure to the smooth side of the Serpentine Belt clockwise around the Belt Tensioner Attachment Bolt. The Standard C4 Corvette Belt Tensioner applies pressure to the smooth side of the Serpentine Belt Counter Clockwise around the Belt Tensioner Attachment Bolt.

Post 156 - Replacing the Serpentine Belt (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-8.html#post1587653773)

Post 275 - The Best Belt Tensioner Pulley (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-14.html#post1594190814)

ZBrink

01-24-2025, 02:12 AM

Did anyone save pictures of rebuilding tensioner? I have a new l98 tensioner coming that I found on Ebay for $35 and Mustang pulley. I have install hundreds of tensioners but never rebuilt one. Any help would be great. If it does not work I will drop off by Marc and let him do it. Thanks

I edited the original post tonight for clarity and context but unfortunately we do not have additional photos of the process at this time. This post has additional pictures but the Op ran into a lot of issues with his rebuild: https://www.zr1.net/forum/showthread.php?t=34691&highlight=Dayco+89298