OFFICIAL MY22+ Tundra/MY23+ Sequoia V35A-FTS (Type '21) Engine Failure Discussion Thread

First technical breakdown I’ve seen. Pretty good watch

https://youtu.be/1XdaccfMxn4?si=fuTAUJWpEWmac92e

spoiler alert, bearing issue not solved but is discussed in length

 

Very interesting re the one piece “ladder frame” crank cap piece. Never seen anything like it.

 

Forgive my ignorance but what is a "bearing tang". I've googled a bit but can't find something that explains what it is.

 

A notch that protrudes out and keeps the bearing locked in place so it doesn’t spin and misalign the oiling orifice.

 

thank you sir

 

An example from when we were building the engine for the boat.


main caps go on top of the cutouts locking everything in place.

 

Pretty common across the industry anymore. The tabs are basically just there for proper alignment of the bearing shell during initial installation. Even the Ford 6.7 turbo diesels do not have tabs on the bearings, and they're making way more cylinder pressure than the V35A or any other gasoline fueled engine does. If the bearing is going to "spin" in the bore, the tabs would shear and not stop it anyway at that point in the event of a lubrication or whatever failure. Toyota and several other manufacturers haven't used tabs for several years and rely on manufacturing tooling for proper alignment of the bearing shells during assembly. All crank bearings are ultimately held in place using crush fit when bearing cap is installed.

 

Who ever made that decision should be hit in the face with a manure shovel.

 

Ever heard of a single piece crank cap?

 

Even the "indestructible" 3UR-FE/FBE 5.7L gen 2/2.5 V8 did NOT have tabs on rod or main bearing shells.

 

Also making less torque in a way bigger package…

 

Yes, single piece main bearing cradle. Honda been using them for years. All the main bearing caps in single casting. Major lower end engine support

 

I added some onto mine with a pair of needle nose.

 

Was about to post that. So the Lexus vehicles have been having issues with this as well and it seems Toyota is not fixing it.

 

Lexus has had some failures since the LS 500 was introduced, just not to the extent as the Tundra…

 

I wonder how many bolts support / hold the cradle and if there are issues maintaining clearance under high load with this new design.

Honda definitely isn’t throwing these torque numbers at their cranks.

 

25…16 of which are for the integrated main caps…

 

https://www.youtube.com/watch?v=Od33wDo5gV8

Not related to the 3rd gen, but the story shows the frustration that service techs at the dealer probably go though with TAS even when they want to do the right thing for the customer.

 

Volvo engine developed in late 1980s has the same ladder-type intermediate section. Spun main bearing is never a thing in this engine, even in high power 300 HP application.



Bolts in recessed cavities is what holds the section to the block. It is crucial to have threading in block holes to be offset in the hole, so the bolt would not pull the metal near the surface and slacken the tension.



Main bearing caps have these offsets:



Holes for bolts that hold the block and intermediate/ladder section have no offset, and this engine model is rarely, but prone to leaking oil along side of an engine:



I would check these holes in V35 engine among the first things to check.

Also notice how main bearings are locked in place. The block side has tabs on both ends:



The counterpart ladder section has only one tab. The other side locks the tab of the block side bearing and prevent any spinning.



This is what I'm talking about, you may even see a mark from the tab:





If Toyota is not doing that, it's super-lame. The problem was solved decades ago, I'm not even sure Volvo was first. Most likely, not.

 

Toyota first used, as far as I can find, the split block/one piece main cap in 1990 on the 1H* Series Diesel engines. The ZZ series was also split. It’s nothing new for them.

I still think the oil feed system, which is non-primary in design, is at least worth a look.

 

Hardly anything new in this engine.

 

From Toyota's engine technician mouth: "We just replace the short block and hope that nothing else got damaged" - that's what I'm talking about those engine repairs. If I fix something for myself and I have a slightest suspicion for a part - it goes to the bin and I pay for a new part. Apparently they can not do that. I don't have to explain why the part is in the bin - I just don't like it and does not want to do the whole job over again, but they do.

 

When is the Tundra due for a mild refresh?

 

2026

 

Can’t imagine them adding anything that will make me want to trade

 

Gen 3.5 hater!

 

Bore and stroke near equal on that application? The fact the stroke is so much more than bore in the new engine is interesting.

22R, 1GR, 2UZ, 1UR, 3UR all have nearly square bore and stroke and this thing V35A - not so much.

 

This exact engine is "The B5254T2 is a 2.5 L (2,521 cc) straight-five. Bore is 83 mm (3.3 in) and stroke is 93.2 mm (3.7 in) with a compression ratio of 9.0:1. It is equipped with a Mitsubishi TD04L-14T turbocharger and intercooled with a power output of 210 PS (154 kW; 207 hp) at 5000 rpm with 320 N⋅m (240 lb⋅ft)[163] of torque at 1500–4500 rpm".

The 300 HP version is "The B5254T4[187] is a 2.5 L (2,521 cc) straight-five. Bore is 83 mm (3.3 in) and stroke is 93.2 mm (3.7 in) with a compression ratio of 8.5:1. It is turbocharged and intercooled and equipped with dual VVT. It produces 300 PS (221 kW; 296 hp) at 5500 rpm with 400 N⋅m (295 lb⋅ft) of torque at 2000–5250 rpm with the 6-speed manual transmission[nb 11];[140] 300 PS (221 kW; 296 hp) at 6000 rpm with 350 N⋅m (258 lb⋅ft) of torque at 1850–6000 rpm[188] with the 5-speed automatic transmission[nb 12]. Cars with the 6–speed automatic transmission[nb 13] were not torque limited."

https://en.wikipedia.org/wiki/Volvo_Modular_engine