Alternator belt removal on 1600k - Updated

[Blokko]

Had a really frustrating time trying to replace the alternator belt on my 1600K earlier today.

 

The bolt at the top of the alternator was banged up so tight that I needed a metre long length of tube on the end of the socket set to loosen it. When I came to the two nuts on the underside of the alternator, the one nearest the nearside skin of the car was already slightly rounded. Again, this was banged up so tightly that I ended up needing a monkey wrench (and a lot of effort) to loosen it up.

 

With both of these nuts now loosened, I expected to be able to move the alternator towards the block to allow easy removal of the old belt. I had to stop at this point as we were due out for lunch, but I just wasn’t getting the amount of movement that I expected (certainly not enough to slide the old belt off easily) - is this normal? I notice that there is a third nut heading back towards the block, midway between the two pulleys - do I need to slacken this off as well?

 

 

Steve - Orange and Black ex Academy

 

Edited by - Blokko on 3 Sep 2007 21:03:57

[CageyH]

There is a tensioner / adjuster on the bottom right hand side as you look at the alternator from the front.

 

Undo this, and the belt comes off easily

 

Only dead fish go with the flow....!

[FlymoFraser]

Blokko

 

I presume you've put the back end back together before starting to take the front end apart 😬

 

 

 

R287 Mobile Jaffa Cake- It's black at both ends with a smashing orangey bit in the middle here

[Blokko]

Neil

 

Just talking things through with my Caterham owner mate (Phil) and commenting on how everything that I attempt with this car turns out to take much longer that I anticipated. Some of this is due to the fact that I don’t have the necessary kit, so end up driving off to Halfords to buy yet more tools (much to the annoyance of SWMBO), but the bulk of it is down to my total lack of mechanical experience.

 

I got the DD tube out and the replacement in without too much drama. The problem came when I tried to reconnect the brake lines - this took ages (as did the subsequent brake line bleed).

 

As per my earlier post, when I turned my attention to an intermittent rattle that seemed to be coming from around the alternator, I found that the belt was split - hence today’s efforts. Hope that this is the last thing I have to attend to with the car before the trip to Ambleside.

 

 

Steve - Orange and Black ex Academy

[Blokko]

Update

 

Having struggled to get the two nuts holding the alternator in place undone, I was surprised that it did not slacken off enough for me to slide the old drive belt out.

 

Tonight I ended up cutting the old belt off. It is at this point that I realised just how little adjustment is available on the alternator - I would say only about 5mm in total. The belt is prevented from being tightened when it hits the tubular chassis. In the other direction (when trying to slacken the belt) it hits the pipes off the oil filter that lead to the Apollo tank.

 

Out of interest I measured up the belt that came off the car and it read 746mm. This is around 10mm more than I expected - can I just put this down to stretching over the 5 years I guess that it has been in place. The old belt seemed correctly tensioned.

 

My real worry is that if I try to install a GMB50735 belt it will be too tight to fit over the pulleys with the alternator set as slack as possible. On that note, any tips on the best way to fit a belt that is a bit on the tight side (where further slackening of the alternator is not an option)?

 

The old belt does not display the Caterham (Unipart?) code GMB50735, but does have PQS100840 and R23667 printed on the back. My mate has both of these codes, plus GMB50735 on the alternator belt of his ex Academy, so I presume that they are the same spec / type of belt.

 

 

Steve - Orange and Black ex Academy

[CageyH]

 

Have you found the adjuster I mentioned????

 

Only dead fish go with the flow....!

[CageyH]

You need to undo the 3rd bolt, where the alternator mounts.

After that, if you follow the slotted piece of metal towards the bodywork, you will find the head of another bolt. You adjust thgis to enable yourself to get the belt on, and tension it up correctly.

 

Any doubts, have a look at a Rover 216 manual or similar. 😶‍🌫️

 

Only dead fish go with the flow....!

[Blokko]

CageyH,

 

Looking from the front towards the back of the car, I’ve undone the nut at the top of the alternator (which gives the pivot for the adjustment), and I’ve also removed the nut and bolt towards the bottom right of the alternator (which I think is the adjuster that you originally mentioned).

 

Having spent ages getting the first two nuts loosened, I was resisting undoing the third nut (bottom left of the alternator, towards the engine block) because I think that the adjustment is restricted by the tubular frame in one direction and the pipes to the Apollo tank (by the oil filter) in the other, rather than having a problem with the alternator adjuster.

 

I could well be missing something due to my general mechanical numptiness, so I’ll go and have another look now…

 

 

Steve - Orange and Black ex Academy

[davidvoas73]

There are 3 large nuts, 14 and 15 mm I think from memory, the top one allows the alternator to "pivot". The bottom left holds the J shaped bracket to the engine block, the bottom right connects the bracket to the alternator. The adjuster is to the right of the bottom right nut, at the right hand end of the bracket, out of view and almost to the right hand side of the alternator. Again from memory I think it is about 8 or 9mm. You need to slacken off all the large nuts and then wind in the adjuster (or is it out?) to move the alternator to the left to create the necessary slack in the belt. Once you have the new belt on you move the adjuster the other way to move the alternator to the right to tighten the belt. Hope this helps...

[Blokko]

Drive belt replacement - in conclusion (particularly relates to 1600k with Apollo tank fitted)

 

For a factory built car where the alternator has not been off before, expect to have a real game loosening off the nuts. Consider getting some spare alternator nuts in case you butcher the old ones (as I did).

 

The amount of adjustment that you will get from the alternator is tiny - only about 5mm movement due to catching the chassis in one direction and the pipes from the Apollo to the oil filter in the other direction.

 

With the above in mind, might be worth considering cutting off the old belt and putting on the new one without trying to slacken off the alternator.

 

I used a 23mm socket to turn the pulley to help get the belt mounted onto the pulleys.

 

Alternator belt - Rover (GMB50735) from Caterham is marked up on the web site as delivered by 1st class post. However, when you come to the checkout you end up with courier delivery @ £11. Ok if you are buying some other kit, but a bit steep for just a belt.

 

Had trouble getting the belt from Halfords / local motor factors / Kia Wolves (who stock Rover parts). Ended up with two equivalent belts that are very slightly longer than the Rover part (one 1mm longer, the other 3mm longer). The Kia parts manager said that they could no longer source the Unipart belt, and would have to order the 738mm belt (one of which I had already sourced from the motor factors next door to where I work).

 

The GMB50735 code means that the belt should have a circumference of 735mm and have 5 ridges along the belt.

 

With the above in mind, I was surprised that the old belt that I cut off was 746mm. Had it stretched that much, or had I got an non standard belt? After some head scratching and a return to basic maths, I realised that the 746mm was the outside circumference of the belt, and allowing for a belt thickness of around 3.5mm, this explains the inside circumference of the belt as 735mm.

 

I’m better at installing document management systems than working on cars, so I’ll be sticking to the day job ❗

 

 

 

 

 

Steve - Orange and Black ex Academy

[Bricol]

But, what we all want to know, is did you find the adjuster bolt - the one that has around 5mm play in itself?

 

Apart from being in an awkward position in a Caterham, it makes belt tensioning a doddle.

 

Bri

[Blokko]

Bri

 

No, I don't think that I did find the adjuster bolt itself, and I’m pretty sure that it is down to my mechanical numptiness rather than some different configuration on my car. I’ll try to get someone at Mid Staffs with more mechanical aptitude than me to show me the error of my ways re this whole alternator belt malarkey.

 

I still can’t see though how I’m going to get any more adjustment given that the movement of the alternator from the top pivot bolt is hindered by obstructions on both sides of the alternator.

 

Main thing is that I’m now back on the road – nice drive into work this morning in the 7.

 

 

Steve - Orange and Black ex Academy

[Ash.Bailey]

did anyone mention the adjuster bolt ?

 

visible from the front underside of the car

 

 

 

If ^It aint ^yellow, wonky ^and wobbly................ 😬