4.6 downgrade to 4.4 question about transmission

[e39 4.6]

Hello everyone, my 4.6 decided it needed 1 less rod in the engine, so it shot it through the block.

my question is about the different torque converter, what's different between the 2 types?

[RRPhil]

The E53 4.6is uses a 280mm torque converter, whereas the 4.4i has a 260mm unit. The bellhousing casting is the same on both transmissions, but the radial webs are machined on the 4.6 to provide clearance for the physically larger converter.





Phil

[PropellerHead]

Originally Posted by RRPhil

The E53 4.6is uses a 280mm torque converter, whereas the 4.4i has a 260mm unit. The bellhousing casting is the same on both transmissions, but the radial webs are machined on the 4.6 to provide clearance for the physically larger converter.


Phil

Damn. Awesome response! I never knew that!

[e39 4.6]

Thanks RRphil, it looks to me like a stronger assembly, is the main difference

[wpoll]

Originally Posted by RRPhil

The E53 4.6is uses a 280mm torque converter, whereas the 4.4i has a 260mm unit. The bellhousing casting is the same on both transmissions, but the radial webs are machined on the 4.6 to provide clearance for the physically larger converter.

Phil

Presumably, the larger TC is to cope with the higher torque output of the 4.6 engine. Is the 4.8 TC the same as the 4.6?

And I wonder which TC the 3.0d (160KW) uses - can't find much info. on that...

[RRPhil]

The ZF six-speed torque converters are different to the 5-speed ones and the different engines each have a different converter matched to them. So, for the 6HP26X transmission, for example:

3.0d = Z83 torque converter
4.4 = L93
4.8 = A84

Returning to the 5HP24 transmissions for the E53; apart from the torque converter/bellhousing, the other key differences between the 4.4i (029) and 4.6is (034) transmissions are :

• The larger L51 torque converter means that the fluid capacity of the 034 transmission is 0.88 litres greater than the 029 model
• The D-brake (which is applied in 3rd and 5th gears) has an extra friction & steel plate for the 034 unit i.e. 5 plates instead of 4
• The upper valve block uses different clutch valves for the B-clutch and E-brake (KV-B & KV-E respectively). Although the casting is the same, the 034 block assembly gets a new part number, 1058 327 075, and so the casting is stamped with the number ‘075’ to distinguish it from the 1058 327 068 assembly used in the 029 model





Phil

[tartilla]

Great info.

Old thread, but better than starting a new one...

I just bought a 2003 4.6is. 80k miles.

I have a receipt for it having a torque convert rebuild installed.

Is there an easy way to access and see if I have the 280mm tq converter?

I should probably change out the fluid and filter, just to make sure the correct fluid is in there, with the correct volume.

[BigBody]

Wonder if RRPhil is still on here... some serious knowledge being laid down!! My question is the differences between 4.8 & 4.4 6 speed auto box’s (aside from T/C).

[wpoll]

Originally Posted by tartilla

Great info.

Old thread, but better than starting a new one...

I just bought a 2003 4.6is. 80k miles.

I have a receipt for it having a torque convert rebuild installed.

Is there an easy way to access and see if I have the 280mm tq converter?

I should probably change out the fluid and filter, just to make sure the correct fluid is in there, with the correct volume.

You don't need to know the total fluid volume to add fluid to the correct level; you fill the trans using a process that ensures the correct fluid volume is added, regardless of what internals are fitted, i.e. filling until the fluid reaches the fill port (at a known temp, with the engine running etc.).

[tartilla]

Originally Posted by wpoll

You don't need to know the total fluid volume to add fluid to the correct level; you fill the trans using a process that ensures the correct fluid volume is added, regardless of what internals are fitted, i.e. filling until the fluid reaches the fill port (at a known temp, with the engine running etc.).

Roger that. I'm more concerned that I've lost the higher stall TQ converter, and the larger diameter fin area of the L51.

Hoping there is an inspection cover, I can get in with an inspection camera.

I saw the the L51 marking was on the face of the TQ converter on a used example.