Belt tensioning, the Arnnworx 920X impressions
#1
Nordschleife Master
Thread Starter
Belt tensioning, the Arnnworx 920X impressions
Ive had the new Arnnworx tension tool for the cam-belt on hand for the last two months meaning to test it out, but i just havent had much time to work on the car and it took much longer than expected to hit the 15k retension mark. Below is a link to Bruce Arnn's webpage which has plenty of information about the 920X aswell as the exact instructions sent with the tool.
http://www.arnnworx.com/
I have no affiliation with Bruce Arnn other than being a happy customer previously.. i have all of his tensioning related tools including the flywheel lock and have used the older AWX belt tensioner.
Anyway i will not get into to much detail about its use, but just want to point out a few areas that some may be interested in knowing before buying the tool. There is not much more i can add about the tool thats not already listed on the Arnnworx page.
1. First off its incredibly easy to use and one of the nicest features about it is that you DO NOT need to constantly take tension readings. The 920X uses a 'live' tensioning for lack of a better term, meaning any changes made to belt tension automatically register on the dial gauge. This takes the guesswork out of setting a tension and hoping you are close by checking with the 9201 tool each time you reset tension.
2. I have used the actual 9201 tool in the past..and to be honest with you ill be damned if i can get consistant results with it. It just seems with the 9201 you constnatly run into space constraints. With the 920X i was able to get the same exact number every single time i retried the tool.
Really there is not much else to say other than this is a great alternative to the 9201. I do not have many pictures of the tool in use as the instructions cover everything fairly well.. but here are a few for the curious,
And here is the dial gauge that you read from...
You basically take 3 readings off the gauge. One with the calibiration bar in place, one of your initial belt tension and one of your final 'within spec' belt tension. Throw in some simple addition and subtraction of decimals and thats it.
From start to finish i was able to retension my timing belt in under an hour and a half. This includes the learning curve to figure out how to use the tool (which is very short). It would have been longer but i do not run with the top half of the belt cover. All you really need to do is move the j-boot out of the way on the 8v n/a cars and remove the distrubutor cap and front cam cover. Removal of the distributor cap and cam cover is not compeltley neccesary, but i think it provides more accurate results using this method.
http://www.arnnworx.com/
I have no affiliation with Bruce Arnn other than being a happy customer previously.. i have all of his tensioning related tools including the flywheel lock and have used the older AWX belt tensioner.
Anyway i will not get into to much detail about its use, but just want to point out a few areas that some may be interested in knowing before buying the tool. There is not much more i can add about the tool thats not already listed on the Arnnworx page.
1. First off its incredibly easy to use and one of the nicest features about it is that you DO NOT need to constantly take tension readings. The 920X uses a 'live' tensioning for lack of a better term, meaning any changes made to belt tension automatically register on the dial gauge. This takes the guesswork out of setting a tension and hoping you are close by checking with the 9201 tool each time you reset tension.
2. I have used the actual 9201 tool in the past..and to be honest with you ill be damned if i can get consistant results with it. It just seems with the 9201 you constnatly run into space constraints. With the 920X i was able to get the same exact number every single time i retried the tool.
Really there is not much else to say other than this is a great alternative to the 9201. I do not have many pictures of the tool in use as the instructions cover everything fairly well.. but here are a few for the curious,
And here is the dial gauge that you read from...
You basically take 3 readings off the gauge. One with the calibiration bar in place, one of your initial belt tension and one of your final 'within spec' belt tension. Throw in some simple addition and subtraction of decimals and thats it.
From start to finish i was able to retension my timing belt in under an hour and a half. This includes the learning curve to figure out how to use the tool (which is very short). It would have been longer but i do not run with the top half of the belt cover. All you really need to do is move the j-boot out of the way on the 8v n/a cars and remove the distrubutor cap and front cam cover. Removal of the distributor cap and cam cover is not compeltley neccesary, but i think it provides more accurate results using this method.
#2
Set to Full-Auto
Rennlist Member
Rennlist Member
This is the next tool I plan to buy from him - I have all the other tools (two flywheel locks) and am very happy with them.
Question - can I use this with the stupid auto-tensioner?
'Nother question - can you convert a car from auto-tensioner to eccentric type tensioner?
Question - can I use this with the stupid auto-tensioner?
'Nother question - can you convert a car from auto-tensioner to eccentric type tensioner?
#3
Nordschleife Master
Thread Starter
Yep, you can use the tool with the spring tensioner. My '87 car (the one in the pictures actually) has the spring tensioner.
And yes i do believe its possible to convert to a eccentric type, i am pretty sure the boss for the stud is there, you just need to drill it out, tap it and throw a stud on. I am pretty sure a few posts have been made in the past regarding this.
And yes i do believe its possible to convert to a eccentric type, i am pretty sure the boss for the stud is there, you just need to drill it out, tap it and throw a stud on. I am pretty sure a few posts have been made in the past regarding this.
#4
Race Director
Bruce absolutely ROCKS!
I bought his original series of tools that were somewhat more crude than what he offers today and have been very happy with them. I have one upgraded tool that is absolutely awesome. And while I have the special tool from Porsche, I'm thinking of getting this tool from Bruce.
I bought his original series of tools that were somewhat more crude than what he offers today and have been very happy with them. I have one upgraded tool that is absolutely awesome. And while I have the special tool from Porsche, I'm thinking of getting this tool from Bruce.
#5
Nordschleife Master
Thread Starter
Geo, i am curious if you are able to get consistant results with the 9201. Perhaps i am just inexperienced with using it. But i personally found that finding enough clearance to press on the belt with the tool with the rear belt cover in the way made it next to impossible to get an accurate reading with it.
#6
Race Director
Originally Posted by Techno Duck
Geo, i am curious if you are able to get consistant results with the 9201.
#7
RL Community Team
Rennlist Member
Rennlist Member
I have some of Bruce's tools and I'm very happy with them. The two 944 wrenches (the pin-wrench which is glorious, and the 27mm wrench which is simple but useful) are both good for my 944 and 968. The 944 flywheel lock and 968 flywheel lock both work well. He had to make my 968 lock when I ordered it, and he had it at my door pretty quick. Next on the list is the 920X!
If I ONLY KNEW he had a tool for the rear wheel bearings, before I tried doing it with common tools.
Rule of thumb: before attempting a new job on the 944, check arnnworx.com to see if there's a tool for it.
If I ONLY KNEW he had a tool for the rear wheel bearings, before I tried doing it with common tools.
Rule of thumb: before attempting a new job on the 944, check arnnworx.com to see if there's a tool for it.
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#8
Drifting
too bad it only works for the timing belt and not the balance belt.
I'm also thinking of buying this, not too expensive, probably what the shop will charge you (or more) everytime you go to have the tension checked.
but how do we know that this new tool gives accurate readings, consistant reading do not mean they are accurate they could be way off but conistant.
I'm also thinking of buying this, not too expensive, probably what the shop will charge you (or more) everytime you go to have the tension checked.
but how do we know that this new tool gives accurate readings, consistant reading do not mean they are accurate they could be way off but conistant.
#9
Nordschleife Master
Thread Starter
I will be checking with the genuine 9201 tool.. but seriously its practically impossible to get accurate AND consistant results with it. Its just extremely awkward to use it, especially in the space constraings available. Having used the original AWX tool and comparing my results with the 9201 results were spot on. I was following the testing of the tool during its development and can say i have all my faith in the accuraey of his new tool.
#11
Techno Duck, how long does it take you to check and retention your t-belt? I just had a top end rebuild and have to bring the car back with-in 1000-1500 miles to have them retention it.
thanks,
TJ
thanks,
TJ
#12
Nordschleife Master
Thread Starter
TJ, i was able to retension my belts in under an hour and a half. That includes setting TDC, removing the distributor cap, rotor and the front cam cover aswell. I also do not have the top portion of the belt cover on my car so everything was ready to be accesed.
#13
Thanks Jon, Hopefully my mechanic will just do it as part of the other large amount of money I paid them for the top end rebuild. :-) But this is something I would like to learn how to do in the future, I am glad to hear people talking about what re-tentioning tools they like.
TJ
TJ