The Triumph Dolomite Club - Discussion Forum

UPDATE whatever number!!

Been a bit quiet over the past couple of weeks but not idle! Had a back spasm through October which prevented any work under my Sprint which has started to ease a bit now. After a couple of chats with mates locally and removing the fan coupling unit, I managed to get a socket and handle in from above to turn the crank pulley bolt, which of course, didn’t turn so I decided to get the sump off again to investigate why. This Tuesday, after that bloody awful struggle to get the sump off – as you’ll all be too well aware of – that isn’t possible unless the starter motor is removed and the engine separated and raised up from the mounts.

With the sump removed I checked the middle group of bearing shells (one at a time) that I’d removed before to check for wear and during this process I found what I thought was the reason for the stuck crank. While looking closely at the centre main bearing cap I could actually see the two crank thrust washers either side of the centre bearing journal but whether they were loose or not I couldn’t tell. After removing the centre main bearing cap and #2 & 3 conrod cap, what I discovered was pretty alarming – not only mechanical damage but my sheer incompetence. I found that despite laying everything out in the correct rebuild sequence, I’d inadvertently fitted the centre main bearing cap (#3) where conrod #3 should go so that conrod bearing cap #3 was in the centre main bearing position!! I can only surmise that I was either disturbed at some point or knocked the components over and refitted them incorrectly. With these bearing caps out of the car, guess what? The crank turned normally!! Doh! Yes, I know - I’m the winner of the numpty award of the year – nay, century!!

While looking at some posts on the club forum and other sites I noticed that from some of the pictures I saw that my bearing shells are probably not as good as I first thought (look at the pics attached). The two conrod shells are from #2 piston and these show a small amount of copper on the bearing face but #3 (not pictured here) looked fine – no copper. As I didn’t remove #1 or 4 conrod shells not sure if these would be the same. My assumption was that for the tri-coated shells, if there is no copper showing on the bearing face then the shell is fine and if only a very small area of copper is showing then this indicates the start of wear. Am I correct in this or not? When new, do the bearing faces show a tin colour or a copper colour? Now look at the main bearing shell. Although I assume no wear, it is quite clearly distorted at the centre of the shell near the oil feed hole and also at the end of the bearing with the keeper tag where it has been compressed and is peened outwards.

I’ll certainly need to replace the centre main bearing shells – and also the other four sets, even though access is difficult with the subframe almost blocking good socket/wrench access. The four conrod sets may also need to be replaced for good measure. The two crank thrust washers are fine. If anyone has recently ordered Sprint bearing shells before, which supplier would you recommend, please, and also, do I actually need to renew the conrod bearing cap nuts? Does all this sound OK?

We have all done similar silly things, so don't be too hard on yourself.
Well done in finding the cause and good luck in putting it back to how it should be.
Phil

Yellow Banana wrote: ↑Thu Nov 07, 2024 4:55 pm UPDATE whatever number!!

..... to get the sump off again to investigate why. This Tuesday, after that bloody awful struggle to get the sump off – as you’ll all be too well aware of – that isn’t possible unless the starter motor is removed and the engine separated and raised up from the mounts.

Hello mate, I'm intrigued by this, I've had the sump off my car about ten times, the only thing I had to do was to lift the engine up a bit on the mounts and twist the oil pan a bit and off it drops...why did you need to take the starter motor off which is a herculean task in itself?

New to this - pic one is the main bearing shell showing the face that sits against the actual bearing cap just to emphasise the distortion. Pic 2 is the same shell showing the journal face with the oil channel.

After a frustrating time last night trying to get my photos to upload to this page I gave up with a massive paddy-on, thinking I'll try again this morning, only to find that judging by user "New to this" post the pictures seem to have uploaded but just not visible on the actual forum page - by clicking on the img icon the pics can then be viewed from the download area. I'll have to have a read of the forum advice on posting pics!!

Shaun Roche - re my sump removal, even with the engine raised off the mounts, the reason for the difficulty is the bolt (which is a long bolt and nut with two thick washers as well) on the nearside rear corner of the sump directly under the starter motor is placed such that I can't get any of my spanners over the bolt top - which is uppermost - without removing the starter motor. I've had the motor off twice while investigating why I broke down - and it certainly ain't easy!!

Yellow Banana wrote: ↑Fri Nov 08, 2024 10:18 am Shaun Roche - re my sump removal, even with the engine raised off the mounts, the reason for the difficulty is the bolt (which is a long bolt and nut with two thick washers as well) on the nearside rear corner of the sump directly under the starter motor is placed such that I can't get any of my spanners over the bolt top - which is uppermost - without removing the starter motor. I've had the motor off twice while investigating why I broke down - and it certainly ain't easy!!

Do you know, I thought that was what you were going to say! Yep, wrestled with that bolt for a good while until I bent a spanner and was able to get on to it - as a Design Engineer, I'm always conscious of access to fasteners when I'm designing etc. and we're even taught DFM now, Design For Manufacture.....believe me, someone will have been conscious of that bolt access, but for what ever reason carried on with the deign....it's like when you look at the design of the body shell, it's actually design to rust, what with all the mud and water traps that have been designed in, purely to make it rust so BL could sell more body panels etc.

Yellow Banana wrote: ↑Fri Nov 08, 2024 10:04 am After a frustrating time last night trying to get my photos to upload to this page I gave up with a massive paddy-on, thinking I'll try again this morning, only to find that judging by user "New to this" post the pictures seem to have uploaded but just not visible on the actual forum page - by clicking on the img icon the pics can then be viewed from the download area. I'll have to have a read of the forum advice on posting pics!!

I downloaded it fine, but it downloaded in a format i'd have to buy an annual subscription to actually see them - so they remain unseen by me!

There are instruction at the head of "Dolomite related" page about uploading pics and the process is so simple even I (a self confessed IT philistine) can do it! Such a philistine I don't know how to link the actual thread!

Steve

What size bearings do you need? I have various good quality tri-metal on the shelf…

What are the crank journals like? If the bearing is worn I’d the crank also in need of work?

Tri-metal bearings when new are silver/grey in colour, no copper visible. If copper visible I’d not re-use them myself.

Here are the pics...

I’d inadvertently fitted the centre main bearing cap (#3) where conrod #3 should go so that conrod bearing cap #3 was in the centre main bearing position!!

That's impossible as they are completely different sizes, unless I'm misunderstanding?

I also agree with Shaun. I've also taken the sump off many times similar to what Shaun said.


If it were me I would be checking the crankshaft with a micrometer. I'm pretty sure that crank will need a regrind.

For non FB users - Update on my sprint breakdown. OK, slow progress to date – well, there aren’t any shows to plan for and, let’s face it, the weather is arse to go out for a ride!!
Took the bearing shells off the big ends and crankshaft to check for wear as reported in last update. The upper mains were a right pig to remove but got them out without any damage elsewhere.
Although the mains looked fine – apart from the distorted one - I took advice from a local engine builder to I replace both mains and big end sets while the bottom end was accessible as it was false economy not to and risk any failures in the near future and, once new shells were received mid last week, I set to replacing them. However, I have only managed to refit the big end shells to hand tight for the mo as I have now found myself in rather a quandary.
I am unable to feed the upper mains over the crank. I’m lubricating the shells and squirting new oil on top and around the crank journals but when trying to slide the new shell into the journal recess it will only partially go in before it tightens up. I’ve tried this on most of the mains but the shell doesn’t want to slide round and I’m wary of tapping them round in case of causing wear to the shell (or journal) if I continue. Yes, I am doing as the manual says – insert the shells with the keeper tab trailing.
After about an hour of this I came to the conclusion that the gap between the journal and the crank case isn’t equal for each main bearing – ie, one side of the case/journal gap is very slightly wider than the other. It dawned on me that this may have been caused by having removed all the main and big end shells in one go and, while turning the crank pulley bolt to assist in the big end shell caps replacement, the crankshaft could now be out of alignment. I think this because with all the shells removed, apart from the crankshaft being attached to the flywheel, the front of the crank shaft is basically free, being only held in place by the front oil seal.
I’ve tried all manner of ideas to try and insert something solid into the crank shaft/case area to hold it in place to see if this might allow the main shells to be inserted but no joy here. I’m thinking now that the only option is to get the engine out, upend it and, working from above, remove the gearbox bell housing, clutch and flywheel. If that’s the case then I’m stuffed as I haven’t got the room in my garage to do this and also can’t turn the car round in the garage to face the door. Sounds like the song “There’s a hole in my bucket, oh Liza, oh Liza”
Any advice gratefully accepted please!!

What has probably happened is the timing chain tensioner has tightened itself up and lifted the crank slightly, just enough to ruin your plans!

But yes, in general it's better to replace one shell at a time under these circs (but with all caps loose or removed) never exactly easy then, it was never designed to be done this way.

However, with the sump off, it's easier to remove the timing cover and access the tensioner to release it a bit, so long as you can get the crank dog bolt undone!

Steve