My engine had a bearing seizure yesterday. The clutch pack does not move. I am told this is a common failure. Also I was told the bearing is integrated into the case and requires a rebuild to fix. Does anyone have a diagram of this part of the engine incl the suspect bearing? Why does this require a full rebuild? Is there anything tricky about replacing this bearing? Lastly, is there anything I did in driving that caused this thing to prematurely fail?
Well this is not good news! If you remove the clutch slave cylinder (near the output coupling) and take out the pushrod what does this look like? I would assume that it has been 'machined' short and maybe with a small point.
If this is the case it is the small roller bearing on the input shaft that has failed and is unfortunately something that is seen sometimes. From our experience it is actually the end of the input shaft where the bearing runs that starts to break up first, this then causes the bearing to collapse.
The bearing is clamped in place between the two crankcase halves so as a minimum the bottom crankcase needs to be removed to replace it. Unfortunately to add to this once the bearing collapses the gearset runs out of a line and in most cases most of it will require replacing, along with the shaft and both bearings obviously. There can also be debris from this sent around the engine (the downside of having the gearbox, clutch and main engine all sharing a set of cases) so it is normally advised to completely strip the engine to ensure that it is completely cleaned out along with ensuring there is no damage to the bearings, pistons, cylinder or any other internal components from any debris.
Lastly you would need to flush through all of your oil lines and dry sump tank along with replacing the oil cooler - you do not want any of this debris to travel around your freshly rebuilt engine.
Apologies for the bad news. How many hours as your engine ran?
Let me know if I can help any further.
Dan, thanks for the input. Wow much worse than I expected. I attached pics of the rod. Engine is a 1340cc. 50 hrs total, 30 on load hrs. Was new in May of 2020.
Far from ideal.
I am fairly sure it is the case looking how 'chewed' up the end of the push rod is. They are 75mm long as standard, how does this measure up?
Well it does not help you I don't think I have ever seen one of these on a 1340cc engine. It has always been put down to the torque of the 1500cc engine - Suzuki have changed the design in this area for the brand new Hayabusa motorbike, which makes me think it must have been borderline anyway.
The car is at the shop so I can't get a measurement today. The engine is coming out and we are going to open the case to see how much damage there is. If we somehow got lucky then maybe we can fix it without the full rebuild and get back on the track soon. Otherwise the engine shops are all backed up for months.
Confirmed the bearing did fail. Tons of loose metal inside. I’ll be ordering a new engine as the lead time is 5-6 weeks vs rebuild which is 3-4 months. I suspect the rebuild cost could exceed the cost of the new engine anyway.
Not ideal, looks to be a lot of debris there.
Hopefully this is not out of place to mention but we could rebuild in a much shorter timescale if you were open to shipping to the UK and happy to run a non 'Radical' engine.
There are a lot of parts in your engine, even at 1340cc, that would reduce the cost of a new build.
Feel free to send me a message if you wanted to discuss further. We have a history with Radical engines and build the Revolution engine 🙂
Just want to given an update on this. 5 months and 3 weeks after I ordered a new engine, it finally arrived. Radical seems to be prioritizing parts for new car builds and not replacements, so if you are debating new vs rebuild, take this into account. It could be a very long wait.
The one good news is that the SR3 engine has a durability upgrade that addresses this weak point. I don't have all the details on the changes, but the engines built this year are denoted by an "X" after the engine number on the upper crankcase. Along with this update is a new spec for 15W-60 oil and new recommendations for minimum on-load temp 55C, and optimum operating temp 95-105C. Both are 5C higher than before. They are saying this oil will push the service interval to 8 hrs from 6.
Old non-X engines can be run with this oil as well.
Very interesting. Has anything been said about overall service interval beyond the 40 hours run time recommended refresh for the new series 1500cc engines?
No mention of changes to the engine refresh schedule. Attached bulletin.
Apparently the list of changes are: input shaft, input bearing, engine cases machined
Very interesting. Run the engine a bit hotter, and use higher viscosity oil to keep low oil pressure warnings at bay.
I just received my 1500 refresh back from Spring Mountain today. Inside is a memo that says "This engine has been fitted with the updated input shaft. This engine MUST now be run with MOTUL 300V 4T 15w-60 engine oil. Failure to run 15W-60 oil will result in engine damage or failure."
Okay. I guess I need to use up my 15w-50 in my other engine.
Interesting, mine arrived 2 weeks ago to dealer shop. I dropped off my car last week, but I did not stick around for opening of the crate. Mine should have similar note since it has improved bearing (that was the source of my engine failure). I will double check.
