Which belts do i need?
#1
Which belts do i need?
I want to order some parts from rockauto and thought i also get some new belts for my
1972 Oldsmobile Cutlass Supreme 350 with A/C and power steering with this order.
I'm a little bit confused with their offering
https://www.rockauto.com/en/catalog/...rive,belt,8900
But i think i need 2 of these
https://www.rockauto.com/en/moreinfo...221691&pt=8900
And 1 of these
https://www.rockauto.com/en/moreinfo...221691&pt=8900
Right?
1972 Oldsmobile Cutlass Supreme 350 with A/C and power steering with this order.
I'm a little bit confused with their offering
https://www.rockauto.com/en/catalog/...rive,belt,8900
But i think i need 2 of these
https://www.rockauto.com/en/moreinfo...221691&pt=8900
And 1 of these
https://www.rockauto.com/en/moreinfo...221691&pt=8900
Right?
#3
Thank you very much!
This helped me figure it out!
https://www.rockauto.com/en/moreinfo.php?pk=3927
https://www.rockauto.com/en/moreinfo.php?pk=3900
https://www.rockauto.com/en/moreinfo...k=3932&jsn=738
This helped me figure it out!
https://www.rockauto.com/en/moreinfo.php?pk=3927
https://www.rockauto.com/en/moreinfo.php?pk=3900
https://www.rockauto.com/en/moreinfo...k=3932&jsn=738
#4
Well i thought i look at the car before placing an order and it looks somewhat off to the "350 Air Conditioning with Power Steering" graphic above to me?
Its also a bosch alternator. I dont think olds used german alternators back in 72?
So what do i do?
Its also a bosch alternator. I dont think olds used german alternators back in 72?
So what do i do?
#5
They didn't. But no telling what's been replaced in 50 years, for example that metal tube upper radiator hose. No Oldsmobile of that vintage ever left the factory with that.
The intelligent way to go about this is to cross-reference the new belts to the numbers on the existing belts. That or take them off, use a belt length gage to measure them, and get new belts of that length.
The intelligent way to go about this is to cross-reference the new belts to the numbers on the existing belts. That or take them off, use a belt length gage to measure them, and get new belts of that length.
Last edited by rocketraider; October 19th, 2021 at 03:36 PM.
#6
Can somebody tell if the belt drive setup is factory using my pictures?
I mean im 99% sure the alternator isn't but that doesn't automatically mean the belts are different than factory.
If the belt drive (and with that the belts) are different i guess i have to measure in order to find the correct belts?
But do i absolutely have to remove the belts for measuring?
I mean im 99% sure the alternator isn't but that doesn't automatically mean the belts are different than factory.
If the belt drive (and with that the belts) are different i guess i have to measure in order to find the correct belts?
But do i absolutely have to remove the belts for measuring?
#8
Can somebody tell if the belt drive setup is factory using my pictures?
I mean im 99% sure the alternator isn't but that doesn't automatically mean the belts are different than factory.
If the belt drive (and with that the belts) are different i guess i have to measure in order to find the correct belts?
But do i absolutely have to remove the belts for measuring?
I mean im 99% sure the alternator isn't but that doesn't automatically mean the belts are different than factory.
If the belt drive (and with that the belts) are different i guess i have to measure in order to find the correct belts?
But do i absolutely have to remove the belts for measuring?
#9
Look at the notes in the diagram Joe posted. You'll see one alternator belt and pulley part # designated as C-49 which is electric grid rear window defogger. I'm guessing C-49 would have had a smaller diameter pulley to increase alternator speed and a corresponding shorter belt. Measure pulley diameter. Someone here will have specs for standard diameter and any optional equipment applications.
Still think the best option is to cross-reference the belt numbers already on the car, especially if they're functioning.
Still think the best option is to cross-reference the belt numbers already on the car, especially if they're functioning.
#10
Today i took pictures of the belts and wrote down the numbers
Gates 6239MC 9.5x1475
Goodyear 15461 11AV1155 3126 41
ACDelco 15565 88934362 440ET 69 70 71 62-0
If i see correctly non of the numbers match in a cross reference ?!?
Going by what i wrote off the belts i think i need these:
https://www.rockauto.com/en/moreinfo...k=3931&jsn=725
https://www.rockauto.com/en/moreinfo...333598&jsn=735
https://www.rockauto.com/en/moreinfo.php?pk=345143
???
If this is correct i think someone at some point did some serious modification to my belt drive system?
Gates 6239MC 9.5x1475
Goodyear 15461 11AV1155 3126 41
ACDelco 15565 88934362 440ET 69 70 71 62-0
Going by what i wrote off the belts i think i need these:
https://www.rockauto.com/en/moreinfo...k=3931&jsn=725
https://www.rockauto.com/en/moreinfo...333598&jsn=735
https://www.rockauto.com/en/moreinfo.php?pk=345143
???
If this is correct i think someone at some point did some serious modification to my belt drive system?
#11
Your current belts are not the factory ones. Obviously they aren't going to match the factory numbers. The diagram I posted are the factory part numbers. Go to RockAuto, use the Part Number Search tab, and key in the numbers from the diagram. For example, here's what you get when you type in the 408310 number for the alternator belt:
#12
https://www.rockauto.com/en/moreinfo.php?pk=3927
https://www.rockauto.com/en/moreinfo.php?pk=3900
https://www.rockauto.com/en/moreinfo...k=3932&jsn=738
But when i go by the numbers i wrote off the current belts
Gates 6239MC 9.5x1475
Goodyear 15461 11AV1155 3126 41
ACDelco 15565 88934362 440ET 69 70 71 62-0
i come up with these:
https://www.rockauto.com/en/moreinfo...k=3931&jsn=725
https://www.rockauto.com/en/moreinfo...333598&jsn=735
https://www.rockauto.com/en/moreinfo.php?pk=345143
These two sets dont match in a cross reference / are different as far as i can tell.
Going by the numbers i think i need the second set?
But this would mean someone altered the belt drive system in the past.
#13
The second set is only about 2" greater in circumference. Math is your friend: a 2" larger circumference is about a whopping 5/8" larger on the diameter (and yes, I realize that the belt isn't a perfect circle, but you get the point). There's far more than that much adjustment in the accessory brackets. Stop overthinking this. Either set works. Personally I'd prefer the smaller ones since belts do stretch as they age. The large ones may be fine with the available adjustment when new, but might push the limits if readjustment is needed. Also, whoever installed the larger ones may have had a limited selection on hand, or may not have wanted to worry about sliding the accessories all the way to the minimum travel position to change the belts.
And since your next thread will be about the new PS pump belt squealing, read this:
And since your next thread will be about the new PS pump belt squealing, read this:
There are THREE fasteners that you need to loosen to adjust the belt, the two bolts on the front and the one nut at the bottom rear of the pump. Once you loosen all three, use a large screwdriver as a pry bar and insert it between the nose of the pump and the tab on the bracket, between the pulley and the bracket. The photo shows the proper position of the screwdriver with the pulley removed for clarity. Use the screwdriver to tension the belt while tightening the two bolts on the front, then get the nut on the back. Failure to do this properly is why there are frequent posts about belts squealing.
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