I would like to get a bit better educated on the different rear axles used in PVs over the years. Questions as follows:

1) I understand there was a 4.56 ratio axle used on earlier models, and later versions had a 4.10 (?). Does the change in ratio accompany the change from B-16 to B-18 engine? Was that late 1960/61?

2) I've seen some views from an on-line parts book (written in Sweedish-I don't read Sweedish), and it apears that these were quite different in design: the differential on the earlier one (higher numeric ratio) removes from the front, the latter from the aft. Do I have this right?

3) I've read about rear axle swaps...120s, P1800s, 140s, even one from a Ford. This is where I really loose it. I guess I'm mostly curious about commonality of parts here, not really interested in changing from drums to discs.

4) If the 120s & P1800s were heavier than a PV, and were equiped from the factory with a B18 & overdrive, I would think a standard B18/OD in a PV would work nicely as long as the rear axle ratios were common with the 120s/P1800. Or would the higher numeric ratio rear axle coupled to an OD offer better flexibility by yielding a snappier response in town & an adequate cruising gear for the highway?

Long story short-what's the desired rear axle (with respect to ratio/driveability/supportability) to use in a PV with a stock B18 & OD?

Thanks in advance for the enlightenment!

Joe in St Louis

1) The change was in '61-'62.

2) 444s came with either an ENV (out the front) or Spicer (out the rear) differential. AFAIK, 544s only came with the Spicer.

3) I think the interesting changes would be 1800E or 140, which use the beefier, but wider, Spicer 30 (most 122s and 1800S used the same Spicer 27 as the 544), or the 9" Ford. There's no commonality of parts, though. If you could find a rear end from one of the later 122/1800S with the 30 ( fairly rare in the US) The swap would be more straight forward, though not much. Still plenty of cutting & welding.

4) Sure, a B-18 with OD works well in a PV. 122 and 1800S ratios were 4.10 W/O OD, and 4.56 with (some 122 wagons had 4.56 W/O OD).

A PV with 4.10s is plenty snappy; the OD gives it a decent cruise.
My only concern with putting an OD in a 544 is that the tranmission tunnel is a stressed member of the unit body; whatever you replaced it with (it has to be cut out for the OD to fit) should be adequate to cary the load or the body will likely fall apart.

Not to proclaim that I am any sort of expert, but I have a hard time believing that the transmission tunnel is so critical to the integrity of the body. It seems to me that the loads would put the floor in tension and the roof in compression, and that the trans tunnel would serve a minimal role. Perhaps in a competition application one would be concerned with maintaining maximum body rigidity, but in a lightly loaded scenario (2 or three passengers driving normally on smooth paved roads), the difference in handling would be undetectable. Is there anybody out there with some real world experience?

Dunno. I went the conservative route and welded my new tunnel in securely. I used a 122 tunnel and it didn't fit too well - the floorboards on a 544 are about 1 1/2 inches lower than the 122 in relation to the drivetrain. So I had to add metal from the bottom edge of the 122 tunnel down to the floorboards. Not hard to do - but I had almost twice as much welding to do. I -think- with the 1800 tunnel the remote shifter might require relocating the handbrake???

I put in the new tranny while the original tunnel was cut out. Now that its welded all back together and I finally took it out for a drive I've discovered that my eBay bargain 1800 tranny ($140 total after shipping) is missing 1st and 3rd syncros. Siggggggh. Pulling it back out won't be as easy with the tunnel in place. I think I'll drive it without 1st and 3rd for a while before I go to the bother of fixing it. Its not too bad - I just can't downshift into 3rd or 1st, and upshifts from 2nd to 3rd work fine if I just wait a couple of seconds. OD works great, however!

I didn't use as much as that of the 1800 tunnel, chopped it in front of the remote bit and kept the pudding stirrer. I had to drop the transmission and found I could get it off the bellhousing using my favourite Snap On allen drive socket with a ball on the end and a long extension. I got the number of the allen socket somewhere if you want it.


Regards



Pete

I'll try to find something similar by the time I decide to pull the tranny back out.

I already found out (several years ago) when replacing the clutch that the bellhousing won't come off the engine on a PV. Close, but no cigar. I couldn't quite believe it as I had done this on 122's, 1800's, and 140's and they all provided enough clearance. I finally had to drop the front crossmember and engine several inches. Made that clutch job just that much more of a chore >:(

I donno John, but a standard trans removes easily from a B18 PV and the bell housing comes out easily too.

Here's a link to my volvo page showing an over drive and tunnel setup.

http://people.delphiforums.com/snotzalot/volvo/neatpv.htm

Not when you are stubbornly trying to remove them together! The pilot shaft ALMOST makes it out of the clutch cover before the bellhousing hits the firewall (only about 1 inch shy of coming out). I can't recall exactly why I didn't remove the tranny from the bellhousing, then remove the bellhousing. I'm thinking there wasn't any clearance in the tranny tunnel to get to those bolts. Mine has hex head instead of allen head bolts - and sockets don't fit well around the curve of the tranny. Should be easier this time with the roomier 122 tunnel.

It wasn't very hard to drop the front crossmember and engine as I only had to come down a couple of inches. So I didn't need to undo any connections to the engine or steering. Just unbolted all 8 (surprisingly small) bolts and jacked the body upwards a couple of inches until the tranny could fit out.

Here is the tool I use.

There were two types of axle fitted to the PV, the ENV, and the spicer. The ENV axle has its diff fitted from the front. The spicer had its diff fitted from the back. The Spicer requires an axle casing spreader.

For the Spicer there was a limited slip diff available.

Two ratios were available for both axles, 4.56 and 4.10, most PV's seem to have low ratio axles, but both ratios were listed. There is no such thing as early and late, the ENV and Spicer were used interchangeably, but very late PV's all have Spicer axles. It is not the case that early ones have ENV's Volvo were using two suppliers.


The axles from 120's, and 1800's don't just bolt on. They lack the mounting for the torque rods on the top of the banjo housing. The diff however can be used out of those axles. Overdrive 120's and P1800's used the 4.56 diff, but they will pull a 4.10 easily for more relaxed cruising. An overdrive in a PV is nice but it won't fit the tunnel without alteration.

For the Spicer axle there are other ratios available since the same basic design was used in Jeeps.


Regards


Pete

Peter,
Thank you for your detailed answer-clears up a lot of questions. But one comment you made has caught my eye... what is an "axle casing spreader"?

The side bearings on the spicer axle are shimmed, ie the ones on the diff carrier through which the halfshafts go. To assemble the axle properly you'll see there are two circular lugs cast into the banjo housing. A whacking great big split steel ring engages in these. This ring has a bolt on it. This physically expands the cast banjo housing to set he preload on the bearing shims.


I agree with Jim, the tranny tunnul is structually critical, I've driven a PV with a flimsy tunnel held in with a few self tappers and it drove with all the structural integrity of a wet sock. On the other hand I've welded the tunnel out of a P1800 into one, and the car was fine afterwards.

Regards


Pete